International Diploma in Occupational
Safety and Health
International Diploma - Course Contents
Unit 2 Safeguarding People’s Health in the Workplace
Element 2A – Occupational Health
Development of Occupational Health 2A1
Occupational Health Provision 2A2
Hazards to Health 2A3
Occupational Diseases 2A4
Monitoring the Health of Employees 2A5
Occupational Stress 2A6
Bullying and Harassment 2A7
Shift Working 2A8
New and Expectant Mothers 2A9
People with Disabilities 2A10
Children and Young Persons 2A11
Alcohol and Drugs 2A12
Element 2B – Risks to Health at Work
Manual Handling 2B1
Ergonomics 2B2
Display Screen Equipment and Workstations 2B3
Hazardous Substances 2B4 Biological Hazards 2B5 Dust 2B6 Asbestos 2B7 Lead 2B8 Radiation 2B9 Noise 2B10 Vibration 2B11
Element 2A: Occupational Health
C O N T E N T S
Study Unit Title
Page
2A1
Development of Occupational Health
THE DEVELOPMENT OF OCCUPATIONAL HEALTH ... 3
THE CHANGING NATURE OF OCCUPATIONAL HEALTH AND DISEASES ... 3
LONG PERIOD FOR IDENTIFICATION OF A NEW OCCUPATIONAL HEALTH HAZARD ... 3
THE RELATIONSHIP BETWEEN OCCUPATIONAL AND PUBLIC HEALTH ... 4
EFFECTS OF EXPOSURE ... 4
MITIGATION TECHNIQUES ... 4
MONITORING ... 4
THE MAIN ELEMENTS OF AN OCCUPATIONAL HEALTH STRATEGY ... 6
THE PLACE OF OCCUPATIONAL HEALTH IN A HEALTH AND SAFETY MANAGEMENT SYSTEM ... 7
OCCUPATIONAL HEALTH NEEDS ASSESSMENT ... 7
PRE-EMPLOYMENT ASSESSMENT AND SCREENING ... 7
HEALTH SURVEILLANCE (HEALTH CHECKS) ... 8
IMMUNISATION... 8
COUNSELLING ... 9
DRUG AND ALCOHOL SCREENING ... 9
TRAINING ... 9
ERGONOMIC ADVICE ... 11
LIFESTYLE SCREENING/ADVICE AND HEALTH PROMOTION ... 12
RETURN TO WORK PROGRAMMES ... 12
DEVELOPING AN OCCUPATIONAL HEALTH POLICY ... 13
RESPONSIBILITIES ... 13
TRIGGERS FOR ACTION ... 13
PROCEDURES ... 13
NATURE OF THE ORGANISATION ... 14
BSC International Diploma |
Unit 2
Element 2A: Occupational Health
Study Unit 2A1 | Development of Occupational Health
Learning Outcomes
When you have worked through this Study Unit, you will be able to:
2.A.1.1 Describe the development of occupational health
2.A.1.2 Explain the relationship between occupational and public health
2.A.1.3 Outline the main elements of an occupational health strategy
2.A.1.4 Explain the place of occupational health in a health and safety management system
The Development of Occupational Health
The Changing Nature of Occupational Health and Diseases
It is likely that the connection between the health of an individual and that person's occupation became apparent at an early stage of social evolution. The first occupational disease could possibly have been silicosis occurring as a result of exposure to flint dust during the
manufacture of flint tools. The development of domestic production of grain could also have led to cases of farmer's lung. However, it would have been the introduction of mining and metal-working that caused the first significant increase in occupational disease resulting from exposure to metal fumes and dust. There appeared at that time, though, to be little concern over the resulting heavy loss of life, due to the fact that the more onerous tasks were
undertaken by slaves and prisoners.
During the 16th and 17th centuries mining, metal-work and other trades flourished, particularly in Italy, following the Renaissance. The development of new trades introduced the use of new materials and processes. Some early texts on the diseases of miners appeared during the 15th and 16th centuries but the first comprehensive treatise on occupational medicine was not produced until 1700 when Ramazzini published De Morbis Artificum Diatriba, from which the modern development of occupational medicine can be directly traced. At that time there was little humanitarian sense or economic necessity to protect the life and health of workmen; consequently Ramazzini's work made little impact on the working environment.
It was the onset of the Industrial Revolution that drastically changed the nature of work, with the development of a vast array of new manufacturing processes, materials and substances, and the creation of a whole range of associated health risks. At the start of this period there was still little incentive to consider the health of the worker. Consequently, conditions in factories and mines were terrible and resulted in great morbidity and mortality. It soon became apparent however, that a sick or dying employee could not work as efficiently as a healthy one and it made economic sense to try to improve the working environment. There is now recognition of the need to conserve the health and efficiency of a skilled workforce. Management and health professionals around the world are aware of the
importance of the relationship between the individual and the organisation and the manner in which it may influence health and well-being. Today, issues such as organisational stress are taken seriously as an occupational health issue. The aim of the modern occupational health team is not only to prevent the adverse effects of physical and chemical agents, but also to ensure that work is adapted to both the physiological and psychological needs of the worker and that, conversely, the worker is fit to do the job.
Long Period for Identification of a New Occupational Health
Hazard
Health hazards often take a significant time to reveal their effects on the body, in comparison to the effects of an industrial accident. For this reason it is sometimes difficult to persuade others of the need for caution and control with occupational health hazards, due to the fact that the effects are often not immediately apparent. Sometimes they are cumulative and the final outcome may not be apparent for some time and possibly irreversible when it is detected. A good example would be asbestos-related diseases. The period between initial exposure and the onset of respiratory diseases such as asbestosis is invariably many years.
The Relationship between Occupational and Public
Health
Many hazards that have been found to affect public health and the environment were first identified or detected in the work environment and/or in the working population. So the occupational environment may act as an "early warning system" and it often provides the information for the provision of preventative action.
Effects of Exposure
A substantial number of hazardous exposures in the community environment are derived from industrial activities or from other occupational systems such as transport. Air emissions generated by vehicles are not controlled by the workplace boundary, and noise levels produced by equipment and machinery in the workplace can cause a nuisance in the nearby community. Additionally, the working population is exposed to the hazards in both the occupational
environment and outside the workplace. Exposure to noise hazards outside the workplace - traffic and aircraft noise being prime examples (heavy traffic (80 dB(A)), jet engines (140 dB(A)) - increase the duration and level of exposure. The cumulative effects of workplace and community exposure may increase the risks of hearing damage.
An occupational health hazard may create a public health hazard. For example, a research institute which handles highly pathogenic agents such as the smallpox virus may, through inadequate control measures, allow transmission.
Mitigation Techniques
There are occasions when methods to decrease exposure to hazardous substances in the workplace lead to increased exposure in the environment and the community outside the workplace. For example, where "end of pipe" solutions such as local exhaust ventilation have been utilised to control workplace exposure an emission to the external atmosphere still exists and there is usually a solid waste that requires disposal. The mitigation technique has
therefore moved the hazard from the workplace to the environment and the local community. However, on the positive side, the shift from the "end of pipe" solutions to primary prevention effectively reduces not only the exposures in the workplace but also limits the numbers exposed and the extent of exposure outside the workplace with reasonable costs. For example, the reduction of noise at source within the workplace will prevent nuisance in the community. Eliminating a hazardous substance or substituting it with a less hazardous substance will remove or reduce exposure to both the working population and the public.
Monitoring
Often the techniques of measurement and monitoring are similar in principle, whether they relate to workplace or public health exposure. Such techniques may include:
Epidemiological studies, which are carried out in both the workplace and in the community to determine cause and effect relationships. Often the results of studies carried out in the workplace identify possible concerns in relation to public health. Studies carried out in both communities are able to provide information for further research and assist in the identification of preventative measures that may be applicable in both environments.
Toxicological data, which can be interpreted and applied to a number of situations. For example, where toxicological data determines a substance to be a possible carcinogen, it is likely to be a carcinogen whether exposure occurs in the workplace or in the
community. Whilst the risk in each environment is likely to vary according to the level and duration of exposure, the hazard remains the same.
Measurement instruments and methods are similar, although interpretation of results and their application may vary slightly. For example, assessment of community noise uses noise level instruments that operate on the same principles as workplace measurement but results are interpreted differently and compared to different standards. Methods of collecting air samples, for example sampling for dusts, will involve a sampling head, pump, filter and flow meter both in the workplace and the community. The sample head, size and type of filter, the rate of air flow and therefore pump type may differ, but the principle of operation and measurement will remain the same.
Many of the techniques and information available to the safety professional in relation to the workplace can therefore be applied in relation to public health.
The Main Elements of an Occupational Health Strategy
Health and safety at work is a general, catch-all term to cover a wide range of adverse effects which may be generated by activities and events which occur at the workplace. Exactly what is covered? We must be clear about the following important definitions:
Occupational health relates to the physical and mental condition of all people at the workplace (employees, contractors and visitors) and their protection from harm in the form of injury or disease.
Safety relates to the conditions at the workplace and applies to the pursuit of a state where the risk of harm has been eliminated or reduced to a tolerable, if not acceptable, level.
The discipline of occupational health is concerned with the two-way relationship of work and health. We are concerned about the effects of the working environment on the health of the worker but we must also consider the influence of the worker's state of health on his/her ability to perform workplace tasks.
A joint International Labour Office/World Health Organisation Committee defined the subject in 1950 as "the promotion and maintenance of the highest degree of physical, mental and social well-being of workers in all occupations".
It is therefore vital that every employer makes arrangements as are appropriate for the effective planning, organisation, control, monitoring and review of the necessary preventive and protective measures having regard to the nature of his activities and the size of his undertaking.
In order to incorporate the concepts of control, monitoring and review of preventive and protective measures, an occupational health strategy must be concerned with:
A primary element for the prevention of ill-health amongst the workforce. This element will involve a wide range of prevention strategies including engineering controls,
procedural controls, workplace design, staff training and supervision.
A secondary element for the early identification of any ill-health that may develop within the workforce. This element will involve health surveillance to try to establish if workers’ health has been harmed by the workplace or its activities.
A tertiary element for the rehabilitation/return to work of any employees who suffer occupational ill-health.
These “Prevention Strategies” are a useful way of considering all aspects of control relating to the prevention of occupational ill health.
The Place of Occupational Health in a Health and
Safety Management System
The discipline of occupational health aims to anticipate and prevent those health problems which can be caused by the types of work which people do. There is a two-way relationship between work and health; in some circumstances environmental conditions at work can
aggravate a pre-existing medical condition. So we are concerned about the general health and susceptibility of the worker, as well as the workplace environmental conditions. When we refer to occupational health and hygiene, we are considering both the (occupational) health of the worker and the hygiene (environmental) conditions of the workplace.
In years gone by the main emphasis in health and safety was on accident prevention and short-term safety issues. Now there is an increasing recognition of the potential detrimental effects of work on health and the need to consider longer-term occupational health issues including topics such as organisational stress.
We shall now consider a number of procedures relating to occupational health which are significant elements in a health and safety management system.
Occupational Health Needs Assessment
Such an assessment should follow a logical and systematic approach, involving:
Recognition of the health hazard.
Quantification of the extent of the hazard by measuring level and/or duration, and relating the measurements to the appropriate workplace exposure standards.
Assessment of the risk to health in the workplace.
Selection and implementation of appropriate control measures.
Such an occupational health assessment requires a knowledge of the range of workplace agents which are able to cause ill-health; understanding of the mechanism of harm; the ability to identify health risks by measurement and comparison with relevant standards; and
familiarity with the range of control measures to enable selection of an effective control strategy.
Pre-Employment Assessment and Screening
In certain circumstances, pre-employment health screening may be appropriate to ensure that employees are fully fit at the outset and able to perform their work efficiently in the
conditions:
For new employees, or those being transferred from one type of work to another, if it is considered that the work is hazardous to health.
Where the worker has to enter a hazardous environment to which he or she has not previously been exposed.
Where there is a high risk of accidents to themselves or others, such as in transport.
Where there is a risk of endangering others through transmission of infection.
Tests and procedures for pre-employment health screening should relate to the demands of the work and the potential hazards it presents and may include vision, hearing and lung function (see below).
Records of pre-employment health screening will provide a base-line measurement of an individual’s health, which can be used as a comparison for any subsequent health testing.
Health Surveillance (Health Checks)
The objectives of health surveillance where employees are exposed to substances hazardous to health in the cause of their work are:
The protection of the health of the individual employees by detection as soon as possible of any adverse changes which may be attributed to exposure to substances hazardous to health.
To assist in the evaluation of measures taken to control exposure.
The collection, maintenance and use of data for the detection and evaluation of hazards to health.
To assess, in relation to specific work activities involving micro-organisms hazardous to health, the immunological status of employees.
Therefore, the purpose of routine health surveillance is to identify, at as early a stage as possible, any variations in the health of employees which may be related to working conditions.
Where hazards are low and the likelihood of occupational disease remote, there may be no necessity for a system of regular health checks. Nevertheless, it is recommended that basic personal records should be kept for all employees, including a historical record of jobs
performed, details of periods of exposure to harmful agents, absence due to sickness or injury, and cause or duration of absence. Where hazards are low but there is known to be the possibility of occupational disease leading to easily recognisable symptoms, self-checks may be acceptable. For medium range hazards checks by a responsible person, such as a supervisor, first-aider or nurse, may be required.
Where there appears to be a higher level of risk, an assessment of the level of surveillance required should be made with the assistance of an occupational physician.
Specific checks which may be carried out on a regular basis due to the hazards relating to certain occupations include:
Audiometry, in order to measure the hearing sensitivity of individuals exposed to noise.
Vision screening, in order to identify any eyesight problems, and to provide effective and remedial action, e.g. providing spectacles for use when working with a VDU.
Lung function testing and chest X-rays to screen people in dusty occupations where there is a risk of pneumoconiosis, and to establish accurate classification of the stages of the disease if it is present.
Blood testing of red and white cell counts by automatic analysis techniques to enable early detection of anaemias and leukaemias.
Immunisation
Vaccines consist of dead or live attenuated organisms that, when administered to individuals, are able to initiate immunity to potentially infectious doses of organisms that could cause
ill-health or disease. Where appropriate vaccines exist, consideration should be given to the vaccination of staff at risk from exposure to harmful organisms.
In some cases, e.g. clinical work where there is a Hepatitis B risk, vaccination may be a requirement before work in high risk areas is allowed to commence. However, vaccination can never be considered to be the principal defence against infection but only as a risk reduction measure. Protection can never be guaranteed since certain individuals may not develop immunity after vaccination. A further problem is the possibility of adverse reaction to the vaccine with some persons. The possible side-effects must be considered before the decision to vaccinate is taken.
The following vaccinations are recommended for particular categories of staff:
Health care workers: rubella, TB, Hepatitis B.
Sewage workers: tetanus, Hepatitis A.
Agricultural/horticultural workers: tetanus.
Counselling
It is now common for many occupational health workers to be trained counsellors. Following a traumatic incident at a workplace, these people are on hand to offer one-to-one counselling for those workers who feel they would benefit from discussing the events.
Other situations where counselling may be used include the following:
Where an employee is suffering from work-related stress.
Where an individual has been subjected to violence from a client/customer in the work situation.
Drug and Alcohol Screening
Random alcohol and drug testing is sometimes undertaken as a deterrent. However, there is an issue as to how random such testing should be. It is important to ensure that employees are available to test, but equally it may defeat the purpose if a warning is given.
Alcohol can be detected and measured in breath, blood and urine. Simple "breathalyser" kits are available for breath testing whereas a laboratory is necessary to quantify the amount of alcohol in blood or urine samples.
Drug testing is much more difficult. Most drugs or their by-products can be measured in blood, urine and saliva. Simple test kits are now available for a range of prescribed and illegal drugs although none are entirely reliable. A positive test does not necessarily mean that the person has taken an illegal drug because the by-products which these tests detect can be formed from legitimate medication. A drug test does not prove whether the person is under the influence of drugs, or whether their ability is affected. All a drug test will do is to indicate if a person has had a certain drug in the recent past.
Training
Health and Safety
In most countries there is a legal requirement for employers to provide health and safety training, while in others it certainly is good practice to provide employees with health and safety training. Such training must normally be provided in working hours and not at the expense of employees.
Training is perhaps one of the key weapons in the management of occupational safety and health as it can be targeted at developing the necessary understanding and skills in individuals and groups. Its success depends on identifying training needs and setting outcomes which can be demonstrated after the training has been received.
The benefits which flow from this includes the following:
New workers, both recruits to the organisation and those changing jobs within it, are able to assimilate the requirements of the job, including aspects affecting occupational health and so become effective quickly.
The correct and safe method of doing the task is learnt from the beginning and, as there is less risk of passing on bad and unsafe practices, machinery and equipment are used more effectively. This means there is less likelihood of exposure to health hazards occurring in the early stages of a worker starting a new job.
Well trained employees, who understand the processes in which they are involved and are skilled in operating them, are more productive and work to higher standards. They also tend to stay longer with the employer, ensuring future reliability and continuity.
There are a number of key points in the organisation when health and safety training is specifically required.
• Induction Training
As a new recruit could be run down by a fork-lift truck on the first day, or a fire could break out soon after his/her arrival. Safety training is, therefore, a priority from the outset.
The induction should also include occupational health hazards and the safe systems of work that are in place to protect employees. This may be collective protection systems such as LEV to keep dust levels down or individual protection such as gloves to prevent dermatitis when working with certain chemicals.
This should precede instruction in the tasks themselves, ensuring that working safety is given precedence. Later sessions should progress to the joint responsibilities of
management and employees for safe working practices and give more detailed attention to the causes and prevention of accidents and fire.
• Job or Process Change
Whenever there is a change to the job or tasks which employees are expected to perform, the employer must arrange for them to receive appropriate training. This applies when individuals change jobs or when there is a change in the nature of the job – through the adoption of new procedures or processes, or the introduction of new technology to it. This is clearly necessary in respect of acquiring the new knowledge and skills necessary for effective performance, but also relates to the implications of the change for health and safety at the workplace. In some ways, experienced workers may be in more need of this than new recruits in that they may feel that, being experienced; they are aware of all the hazards and risks and know what to do.
Allied to situations where the job changes are situations where the skills necessary for effective performance for an existing job or role change. A good example of this is in respect of first aiders who need to keep their knowledge and skills up-to-date and should go on regular refresher training courses.
Occupational health hazards are often less obvious than typical safety hazards, e.g. the risk from exposure to X-rays is much less apparent than that from unguarded moving machinery. It is therefore especially important for workers who are exposed to health hazards to receive explicit training and instruction on the risks to which they are exposed and the precautions that should be adopted to reduce the risk of harm.
• Changes in Legislation
The area of health and safety is often regulated by the law (although this differs from country to country) and employers should ensure that they comply with its demands at all times. This means that, as laws are amended or new legislation is passed, they must set up procedures for implementing the new requirements.
There are two aspects to this:
− A need to monitor developments to ensure that they are aware of impending changes
and can take the necessary action.
− A need to provide structured training to all staff – management and workers – who
will be affected by it.
Manual Handling
To ensure competence in manual handling techniques, appropriate instruction and training should be provided. This should be closely related to a person's job and include theoretical and practical supervised sessions using typical loads in working conditions to ensure a thorough understanding of, for example:
The design of the tasks involved.
Recognition of different types of load, e.g. assessing the likely weights of loads and deciding which may or may not be handled without assistance.
The need for good housekeeping in and around the work location.
Safe lifting and handling techniques, including the risks from careless and unskilled handling.
Correct use of personal protective equipment.
Correct use of mechanical aids.
First-Aid
First-aid is the immediate and temporary care given to the victim of an accident or illness until the services of a qualified medical practitioner can be obtained. It can save lives and
minimises the consequences of an injury until medical help is obtained, so every workplace should have sufficient trained personnel and suitable facilities to deal with any cases which occur. It also has another function - the treatment of minor injuries which would not receive or do not need medical attention.
Ergonomic Advice
The ergonomic design of tools, equipment and workplaces can contribute to the reduction of risk relating to occupational health and safety.
Appropriate design can reduce the levels of force required for a task, the number of highly repetitive movements, and improve posture. Mechanisation and automation and reducing machine pace can also have a major impact on the risk.
Lifestyle Screening/Advice and Health Promotion
Increasingly advice is available, and should be promoted within the workplace, on the benefits to the individual that can be gained from a "healthy" lifestyle. Campaigns to encourage individuals to stop smoking, eat healthily (five portions of fruit and vegetables a day, less fat, less salt, etc.) and drink only moderately are only some of the better known ones.
Also to be promoted are certain advisory promotions (safe sex) and self-screening campaigns, such as regular examination by men for testicular cancer and by women for breast cancer.
Return to Work Programmes
Employers wishing to see their staff re-introduced into the workplace following a period of absence must carefully manage the process if they are to prevent further absence due to a recurrence of the existing problem or the development of another one.
There is a need for an employer to fully understand the nature of an employee’s condition in order that they can develop an agreed return to work programme that is appropriate and long lasting.
Advice is often taken from the employees’ medical practitioner, via sickness absence notes or other documentation which will provide details about the ailment and any possible limitations on the individual including possible side effects of any continued treatment. It is vital that the company engage in continuous dialogue with the employee to understand the problems and to show that they care. Occasional visits by a company representative and informal meetings to discuss progress and concerns are invaluable in maintaining good relationships and helping the employee to return to work.
It is often desirable to consider a phased return to work programme, which is agreed between all parties. In this way the employee can gradually be re-introduced to working life until such time as they feel comfortable working at the level they were at before their absence. This time can be very difficult for the employee, especially if they were involved in projects or
committees and their place has been filled (even temporarily) by someone else. Employers d must be sensitive to this issue if they are to avoid further unrest and ill health that might be seen as a consequence.
Developing an Occupational Health Policy
Effective management of any issue requires the development, communication and
implementation of a policy. Occupational health is no different. The O.H policy should be documented and consistent with the overall business aims and policies within the organisation.
Responsibilities
The roles, responsibilities and authority of those people who manage or perform occupational health functions should be defined, documented and communicated. Ultimate responsibility for occupational health lies with top management but the responsibilities of all employees, including line managers and lower-levels of employees, need to be clearly defined. Specialist areas should not overlap and boundaries should be clear.
Every person should understand their responsibilities and be competent to perform them.
Triggers for Action
Depending on the organisation, the risk associated with the activities and the type and level of occupational health service, there may be a number of triggers for action. Action may be mainly reactive in nature, i.e. waiting for issues to arise before taking action, or it may be proactive by getting involved in issues such as health screening and education. Clearly, in some organisations legal requirements may well determine the triggers for action and what those actions should be.
The policy should identify the services available and when they are applicable such as:
Pre-placement screening and fitness to work.
Sickness absence and rehabilitation.
Education and promotion.
Rehabilitation of people who are ill, whether or not caused by work, to keep them in work or enable them to return to work.
Procedures
A major part of occupational health will be to look at all the factors of new working practices, equipment and materials. Procedures will need to be in place to identify changes in operations and to assess the risks they present to enable the occupational health service to adjust
according to changing needs. Consideration should be given at the planning stage to the design of jobs and the application of ergonomic and human factor principles.
Depending on the type and level of service provided procedures will need to be in place for a number of issues including:
The identification of workplace hazards that present risks to the health of employees.
Accessibility of the service, for both employees and for manager referrals.
Reporting and investigation of complaints and incidents.
Confidentiality of employee records.
Sickness absence management including self-certification, absence review and long-term absence management.
Disciplinary and grievance procedures.
Mandatory and voluntary health screening requirements and options.
Pre-employment screening.
Education, promotion and communication.
Rehabilitation and return to work services.
Monitoring and review of the service and occupational health risks.
Nature of the Organisation
There is no single model of what is a good occupational health scheme; each scheme depends on the nature of the organisation, its size, the kind of work involved and the service it
provides. The development of the policy will need to consider these organisational factors to determine the type and level of service to be offered. Individuals with health conditions or impairments requiring additional control measures, or the existence of work activities requiring extensive physical exertion may impact service determination. The service may be provided internally, outsourced or combined. It may be appropriate to employ a single occupational health nurse or a team of occupational specialists. The variability of each organisation’s requirements makes a detailed assessment of needs important prior to developing the policy.
Typical Occupational Health Policy
A typical Occupational Health Policy might include the following topic areas:
Policy aims and objectives.
Organisation & responsibilities of health provision.
Risk assessment.
Stress.
Bullying and harassment.
New and expectant mothers.
Disabilities.
Working hours.
Children and young persons.
Alcohol and drugs.
Sickness absence.
Health surveillance.
Ill-health reporting.
Rehabilitation/post sickness assessment.
Employees’ occupational health surveillance questionnaire.
Disabled employees and students.
First aid facilities.
Element 2A: Occupational Health
C O N T E N T S
Study Unit Title
Page
2A2
Occupational Health Provision
THE COSTS AND BENEFITS OF OCCUPATIONAL HEALTH PROVISION ... 3
REDUCING COSTS BY IMPROVING HEALTH MANAGEMENT ... 3
COMPLYING WITH LEGAL REQUIREMENTS ... 3
MORAL DUTY OF CARE ... 4
INTERNAL AND EXTERNAL OCCUPATIONAL HEALTH PROVISION ... 5
INTERNAL PROVISION ... 5
EXTERNAL PROVISION ... 5
THE ROLES OF MEMBERS OF THE OCCUPATIONAL HEALTH TEAM ... 7
OCCUPATIONAL HEALTH PHYSICIANS ... 7
OCCUPATIONAL HEALTH NURSES ... 8
COUNSELLORS ... 8
PHYSIOTHERAPISTS ... 9
ERGONOMISTS ... 9
BSC International Diploma |
Unit 2
Element 2A: Occupational Health
Study Unit 2A2 | Occupational Health Provision
Learning Outcomes
When you have worked through this Study Unit, you will be able to:
2.A.2.1 Explain the costs and benefits of occupational health provision
2.A.2.2 Explain the relative benefits of internal and external provision
2.A.2.3 Describe the roles and responsibilities of members of an occupational health team
The Costs and Benefits of Occupational Health
Provision
Reducing Costs by Improving Health Management
Ill-health can be costly and the indirect costs involved are often substantially more than direct costs.
In some countries employers are required to have certain types of insurance against accidents, ill-health or other problems, such as:
Employers' liability insurance.
Public liability insurance.
Motor vehicle insurance.
These insurances will cover some of the costs of ill-health. However, many of the costs cannot be insured against, such as:
Lost production time.
Legal costs in defending civil claims, prosecutions or enforcement action.
Overtime and other temporary labour costs to replace the injured worker.
Time spent investigating the cause and other administration costs (including supervisor's time).
Fines from criminal prosecutions.
Loss of highly trained and/or experienced staff.
Effects on employee morale and the resulting reduction in productivity.
Bad publicity leading to loss of contracts and/or orders.
Any reduction in costs that can be achieved by improving health management will be of benefit to the organisation. Such reductions may be achieved, for example, by:
Raising employees' awareness of health hazards by means of training, signs, notices, etc.
Implementing occupational health techniques such as:
− Health surveillance.
− Hand inspections for those who work with wet cement. − Using low vibration equipment.
Purchasing policies, e.g. selecting personal protective equipment that not only provides adequate protection, but is also provided in different sizes.
Measures such as these will contribute to the prevention of occupational ill-health resulting in less likelihood of civil action being taken by employees against the organisation.
Complying with Legal Requirements
There are strong legal reasons for employers to manage risk by providing occupational health provision:
Punitive - where the criminal courts impose fines and imprisonment for breaches of legal duties. These punishments can be given to the company or to individuals within the company.
Compensatory - where employees are able to sue for compensation.
The provision of occupational health services will reduce the risk of ill-health occurring amongst employees, and thus reduce the chances of legal action being taken by employees against the employer.
Moral Duty of Care
It is widely accepted that moral reasons should be the prime reason for managing risk and providing occupational health care, although whether this is actually the case is open to debate in some cases.
There is a need for maintaining a moral code within our global society. Without it, employers can be tempted to treat the health and safety of the workforce as being of lower importance than financial profit.
Moral reasons are based on the concept of an employer owing a duty of reasonable care to his employees. A person does not expect to risk life and limb, or physical health, as a
condition of employment.
Society expects every employer to demonstrate a correct attitude to health and safety to his workforce. It is totally unacceptable to place employees in situations where their health and safety is at risk.
In addition to the obvious duties owed by an employer to his workers, he also has a moral obligation to protect other people whose health and safety may be affected by his undertaking, e.g. contractors or members of the public.
When determining the type and level of Occupational Health provision an organisation should first carry out a needs assessment to ensure the service will meet their needs. The needs assessment can be carried out by the organisation itself or by an external provider and should consider such factors as:
The size of the organisation.
The geographical spread of the workforce.
The variety of occupational health hazards within the organisation.
The availability of facilities.
Internal and External Occupational Health Provision
There are advantages and disadvantages associated with both internal and external provision for Occupational Health services. The main advantages are as follows:
Internal Provision
The most effective occupational health provision will be achieved where the occupational health team has a true understanding of the organisation's activities, priorities and values. An internal team is often in a better position to become an integral part of the
organisation, gaining both an operational and strategic understanding which allows the service to become more tailored to the needs of the organisation.
An internal team is in a position to establish relationships within the organisation and gain best use of the internal resources available from within other areas of the business. They become familiar with organisational structures, both formal and informal, and can make effective use of working relationships.
The organisation is in a position to select occupational health professionals with
personalities that meet the needs of the organisation and in-house teams can be trained and developed to the specific needs of the organisation.
An in-house occupational health team generally allows employers and employees easy access to health advice. There is also no requirement for employees to leave the
workplace, reducing time away from work. However, where occupational health provision is through just one or two individuals, there is always the risk of health professionals not being available when they are needed due to absence.
Assuming staff turnover is low, an in-house team can achieve continuity as the occupational health team is likely to remain stable.
When offered internally the type or level of service is generally more flexible and is able to change frequently and with little cost when the needs of the organisation change.
An equivalent service is likely to be cheaper if provided internally, but the availability of a whole range of services from externally-sourced providers may outweigh that benefit.
External Provision
Occupational health is a specialised area which may be difficult to manage internally; outsourcing the service removes the need to manage the service leaving only the requirement to manage the contract.
An outsourced service is likely to have access to a broader range of professionals and specialist services, with professional development likely to be an ongoing part for each professional ensuring that access to up-to-date advice is constantly available.
Where an employer uses an external company, the need to provide, maintain and equip premises are removed. In terms of financial resources this can be cost effective. In addition where an organisation is geographically spread, with employees in different parts of the company, an external provider is likely to be able to provide facilities in a number of more accessible locations.
Generally, access to an outside service will always be available. Whilst the individual health professional seen may vary, the outsourced company usually has the resources to cover for absence.
The levels and type of service provided by external companies are extremely varied and can be selected according to the needs of the organisation. The experience and
knowledge of the external provider are likely to be of real benefit when establishing the service required.
The Roles of Members of the Occupational Health
Team
The provision of an occupational health service to the workforce requires the involvement of a range of professionals including Occupational physicians, Occupational nurses, Counsellors, Occupational hygienists and Ergonomists.
A hypothetical example of the combined approach working in practice could be:
The recognition of a particular health effect by a worker, safety representative, nurse or doctor.
Diagnosis of the illness and treatment by a nurse or doctor.
Discovery of the environmental cause by a hygienist.
Implementation of controls by the employer assisted by the hygienist or ergonomist. We shall now look at the roles of the various occupational health specialists.
Occupational Health Physicians
We can divide occupational health into two convenient elements: occupational hygiene, concerned with the measurement and physical control of environmental hazards; and the discipline of occupational medicine. This is the branch of preventative medicine concerned with the diagnosis and assessment of health hazards and stresses at work. Since it is a specialist branch of the medical profession, we need a medical practitioner to carry out this function. This type of doctor is referred to as an Occupational Health Physician. The
occupational health section provides a range of services, and the exact division between those which directly involve the occupational health physician and those carried out by an
occupational health nurse is often not clear-cut. However, below are some common functions which the occupational health physician may carry out directly or supervise.
Statutory Medicals
Certain workers are required by specific regulations to be examined periodically for
occupational health reasons. Examples include ionising radiation, lead and asbestos workers.
Health Surveillance
Best practice requires health surveillance in given circumstances to facilitate the early detection of disease or adverse health effects, and to assist in the evaluation of control measures. The process may involve examination of possible exposure to carcinogens, pathogens and
sensitisers. Where exposure to such substances exists, the role of the occupational health physician will be to decide if health surveillance is necessary and whether a method of health surveillance is available which is capable of identifying adverse health effects related to the working environment, and which has a useful predictive value.
Pre-Employment Health Assessment
One of the valuable services offered by the occupational health section to management is expert advice on the fitness of applicants and employees. Sometimes it can be done through a health questionnaire assessed by the occupational health nurse. However, where a higher level of medical fitness is a job requirement, or where a medical opinion is required in a more
complex case, the occupational health physician will carry out a pre-employment medical examination.
Post-Sickness/Rehabilitation/Ill-Health Retirement Health Assessment
In some circumstances, such as with food-handlers or after long periods of sickness absence, it may be necessary for a return-to-work examination to take place. This creates the opportunity to advise on the person's fitness to return to work, or perhaps recommend some form of rehabilitation first. In cases where persons are suffering from a medical condition likely to prevent them from continuing work, the occupational health physician will carry out a medical examination and possibly advise on ill-health retirement.
Occupational Health Nurses
Occupational health nursing is a specialist branch of the nursing profession. The training which the qualified occupational health nurse undergoes enables that person to:
• Assist the employer in complying with health and safety legal responsibilities. • Monitor the health of employees.
• Promote good health activities in the workplace.
The basic role, therefore, is to prevent occupational ill-health and to improve the health of the workforce generally. The training of the occupational health nurse encompasses areas of health and safety familiar to the health and safety practitioner, and also aspects of the type of workplace monitoring carried out by the occupational hygienist. Consequently, the
occupational health nurse should be familiar, for example, with noise at work and be able to carry out simple noise surveys to locate areas of concern and be able to implement an
audiometry programme to screen for noise-induced hearing damage.
The following elements of an occupational health programme would heavily depend on the involvement of the occupational health nurse:
• Working with line managers to minimise hazards, ensure compliance with health and safety legislation and implement the organisation's occupational health policies. • Dealing with cases of substance abuse.
• Advising on placement at work through pre-employment health assessments. • Health surveillance after return to work from accident or ill-health.
• Managing health centre facilities, offering basic health checks and co-ordinating first-aid services.
• Advising on ergonomic issues.
• Promoting good health education and activities in the workplace, geared to encouraging employees to take personal responsibility for their health.
• Providing advice and counselling.
Counsellors
Trained counsellors can be of benefit to those who have been involved in traumatic situations, ranging from involvement in a major accident to suffering stress due to pressures in the work situation. Counsellors do not give advice; rather, they encourage individuals to talk about their thoughts and feelings knowing that they will not be exposed to any criticism or judgment.
Counselling can give significant mental relief to individuals suffering in various ways.
Physiotherapists
The role of the occupational health physiotherapist includes the assessment, diagnosis,
treatment, evaluation and follow-up of work-related injuries and diseases. The physiotherapist provides rehabilitation in order to help injured employees back to work or to assist them to remain at work.
Activities and responsibilities undertaken by an occupational health physiotherapist may include any of the following tasks:
Workplace assessments and making recommendations for alterations.
Analysing tasks and suggesting changes in order to avoid injuries.
Education/training relating to injury prevention in the workplace, e.g. back care, manual handling techniques, etc.
Testing a person's capacity for work.
Treatment of work-related injuries.
Planning return-to-work timetables for injured employees.
Implementing stress management and relaxation techniques.
Pain management.
Ergonomists
The work of the ergonomist can have important implications for the smooth running of the workplace, with regard to efficiency, productivity, safety and health. It is the ergonomist who aims to ensure that the individual and the technological setting in which he/she works combine to get the best performance available from both resources.
The ergonomist is concerned with:
The design of equipment and systems so that they are easier to use.
The design of jobs and tasks so that they take account of human factors.
The design of equipment and the work situation in order to improve posture and strain on the body to avoid repetitive strain injury and work related upper limb disorder.
The design of work environments to ensure that elements such as lighting and heating suit the requirements of the individual whilst carrying out the necessary work.
The ergonomist works in multi-disciplinary teams which may include design engineers, industrial designers, production engineers, health and safety specialists and psychologists.
Occupational Hygienists
Hygiene is generally considered to be the maintenance of health and the prevention of disease. Occupational hygiene applies this definition to the place of employment and the principal aim is to prevent occupational ill-health.
The work of the occupational hygienist follows the stages used in the study of occupational health and hygiene generally:
• Assessment of the risk.
• Measurement of the risk and interpretation of the result. • Application of control measures and their maintenance. • Information, instruction and training.
However, the key speciality of the occupational hygienist is the measurement of risk and interpretation of results. A wide range of monitoring techniques is available, making use of special equipment and instruments. The occupational hygienist is trained in their selection and use, but most importantly, in the interpretation and evaluation of the results which they provide.
As inhalation is the most important method of entry of a toxic substance into the body, much of the work of the occupational hygienist involves measurement of airborne contaminants, using personal or static samplers and comparing the results. The correct sampling
instruments, methods and analytical procedures must be identified.
As well as airborne dust, gas and vapour, the occupational hygienist is also concerned with measurement of heat, noise and other pollutants. Another important area of involvement is the monitoring of control measures to ensure they are working effectively. Consequently, the occupational hygienist is skilled in carrying out measurements on ventilation systems and other environmental control devices to ensure they operate at optimum performance.
The Work of an Occupational Hygienist
The routine work of a hygienist is to ensure that the work environment does not cause ill-health and that levels of exposure are in compliance with the statutory limits for chemical, physical and biological agents.
Recognition of Hazards
Avoidance of ill-health at work is achieved primarily by identifying the many visible and hidden environmental hazards, present or emanating from the workplace. Key categories of such hazards are:
Chemical (dust, fumes, gases, vapours; also those harmful by skin contact).
Physical (extreme temperatures, light, noise, vibrations, ionising and non-ionising radiation and humidity).
Microbiological (bacteria, viruses).
Behavioural or psychosocial misfit (stress caused by excessive work demands beyond a person's ability to cope, violence and bullying).
Ergonomics, or physical misfit (factors affecting posture and motion, manual handling). Hygienists need to be aware of the legal requirements and standards. They should also be aware of the environmental impact of their activities, and integrate occupational health practice with environmental protection.
Evaluation of Risks
Occupational hygienists understand how hazards might affect health, and can measure how serious the effects may be. The hygienist must understand the routes of entry into the body of various agents, as well as the effects on health.
The evaluation of risks typically comprises a study of existing plant, equipment, materials used, products and by-products, production and general working conditions.
Atmospheric monitoring may be passive, i.e. using a static monitoring position, or personal, where the worker wears a detection/collection device whilst carrying out normal work practices.
Risks to persons outside the workplace may also be relevant.
Control of Risks
Occupational hygienists specialise in eliminating the risks to health or controlling them in practical and cost-effective ways by the application of scientific, technological and managerial principles. Any problems identified should be rectified, following a hierarchy of the most practicable controls or isolation of the hazardous agent. They should endeavour to develop strategies, if necessary working together with professionals from other disciplines, which will contain the harmful agents near to their source. Organisational measures, and education, go hand-in-hand with technical measures such as enclosure, segregation and local exhaust ventilation.
The supply of suitable personal protective equipment is a last resort, as this has its own inherent problems of isolation and discomfort.
Measurement and Monitoring of Health Hazards
The practical skills of occupational hygienists cover the development of technical monitoring methods, the measurement of exposure, such as required as data for a risk assessment, or to monitor the effectiveness of controls. The hygienist must interpret the results and explain them to both management and workers including those involved in personal monitoring. Monitoring and review of the organisational aspects, and of the work environment (e.g. by measuring noise, dust, etc.) together with appropriate indices of workers' health, ensure the feedback loop is closed.
Element 2A: Occupational Health
C O N T E N T S
Study Unit Title
Page
2A3
Hazards to Health
THE MAIN OCCUPATIONAL HEALTH HAZARDS AND ASSOCIATED RISKS ... 3
PHYSICAL HAZARDS ... 3 CHEMICAL HAZARDS ... 6 BIOLOGICAL HAZARDS ... 8 PSYCHO-SOCIAL HAZARDS ... 10 ERGONOMICS ... 11 LIFESTYLE ... 12 THE EFFECTS ON THE BODY OF THE MAIN HEALTH HAZARDS ... 15
HUMAN PHYSIOLOGY ... 16 RESPIRATORY SYSTEM ... 16 DIGESTIVE SYSTEM ... 17 CIRCULATORY SYSTEM ... 18 NERVOUS SYSTEM ... 18 SKIN ... 18 THE EYE ... 19 THE EAR ... 20 EFFECTS OF OCCUPATIONAL HEALTH HAZARDS ON THE BODY ... 21
PROCESS OF ENTRY ... 21 ROUTES OF ENTRY ... 23 LOCAL AND SYSTEMIC EFFECTS ... 24 ACUTE AND CHRONIC EFFECTS ... 24 TARGET ORGANS ... 26 THE BLOOD ... 26 THE LIVER ... 29 THE KIDNEYS... 29 THE REPRODUCTIVE SYSTEM ... 30 DEFENCE MECHANISMS ... 31
INHALATION AND RESPIRATORY DEFENCES ... 31 DEFENSIVE CELLS ... 34 OTHER DEFENCE SYSTEMS ... 39 THE FUNDAMENTAL ELEMENTS OF TOXICOLOGY ... 40
LETHAL DOSE (LD50) ... 40 LETHAL CONCENTRATION (LC50) AND LETHAL TIME (LT50) ... 42
NO OBSERVED ADVERSE EFFECT LEVEL (NOAEL) ... 43 TYPES OF TOXICITY TEST ... 43 THE FUNDAMENTAL ELEMENTS OF EPIDEMIOLOGY ... 45
ROLE OF OCCUPATIONAL HEALTH SPECIALISTS ... 45 TYPES OF EPIDEMIOLOGICAL STUDIES ... 46 CONTROL AND PREVENTION STRATEGIES ... 49
BSC International Diploma |
Unit 2
Element 2A: Occupational Health
Study Unit 2A3 | Hazards to Health
Learning Outcomes
When you have worked through this Study Unit, you will be able to:
2.A.3.1 Describe the main occupational health hazards.
2.A.3.2 Explain the effects on the body of the main occupational health hazards
2.A.3.3 Outline the principal elements of toxicology and epidemiology
The Main Occupational Health Hazards and Associated
Risks
These occupational health hazards fit into six categories: • Physical
Noise, vibration, radiation, heat, etc.
• Chemical
Liquids, gases, vapours, dusts, fibres, etc. and the associated hazards. • Biological
Bacteria, virus, fungus, mites, insects, etc. • Psycho-Social
Working hours, relationships, stress, etc.
• Ergonomic
Manual handling, workplace layout, etc. • Lifestyle
Smoking, drinking, lack of exercise, dangerous sports, etc.
We shall study many of these occupational health hazards throughout this study unit.
Physical Hazards
Noise
We are surrounded by sound all the time – we use it as a means of communication and as a source of entertainment (music), and we also use it as a source of information about our environment. Without it, we may become disorientated. However, in certain circumstances, it can be an intense irritation and a considerable hazard at work. In such circumstances,
unwanted sound is usually referred to as noise. The major problem of noise is hearing damage, but it can also cause disturbance which can impair efficiency and interfere with communication which increases the risk of accidents, and stress.
In moderation, noise is harmless, but if it is too loud it can permanently damage hearing. The danger depends on how loud the noise is and how long people are exposed to it.
The effects may be acute or chronic:
Acute effects are where the peak pressure of the sound wave may be so great that there is a risk of instantaneous damage to the mechanisms of the ear. This is most likely when explosive sources are involved such as cartridge-operated tools or guns. The effects of such trauma to the hearing senses may be permanent or temporary.
Chronic effects are where constant exposure to excessive noise over a period of time gradually produces damage to the hearing senses. This form of damage may not be noticed until it has become permanent, although some effects may recede with time.
Generally, such damage to hearing is irreversible. Surgery may reduce the damage in the case of acute injury to the eardrum, but there is no cure for hearing impairment.
The effects of damage to the hearing mechanisms of the ear may take a number of forms.
Sounds become muffled so that it is hard to tell similar sounding words apart, or to pick out a voice in a crowd and it is difficult to distinguish speech from background noise. This effect is known as “threshold shift”, indicating that the level at which sounds can be clearly distinguished has reduced. The condition may be permanent or temporary.
Noise induced hearing loss occurs where the ear is unable to respond fully to sound within the speech range. The person does not necessarily lose the ability to hear sound, but is unable to distinguish the spoken word clearly even if it is presented with a raised voice.
Tinnitus is a subjective condition where “noises in the head” or “ringing in the ear” are the descriptive symptoms. There are no observable external symptoms. This may be an acute condition which recedes with time, although the recovery period could be 12 or more hours where very high exposure levels occur. It may also occur with people who have a chronic noise-induced hearing impairment, in which case it is usually permanent. Where conditions in the workplace are such that it is necessary to shout in order to be understood, or there is a difficulty being understood by someone about two metres away, there is likely to be a problem.
Vibration
Regular exposure to hand/arm vibration can cause a range of permanent injuries to hands and arms, collectively known as hand/arm vibration syndrome (HAVS). The injuries can include damage to the blood circulatory system (e.g. vibration white finger), sensory nerves and muscles. Pain and stiffness in the hands and joints of the wrists, elbows and shoulders may also occur.
The injuries can be painful and disabling, e.g. painful finger blanching attacks (triggered by cold or wet conditions); loss of sense of touch and temperature; numbness and tingling; loss of grip strength; loss of manual dexterity; and inability to pick up small objects. The condition can affect work and leisure activities. People may need to avoid further exposure to vibration, or cold and wet conditions; and have difficulty handling tools and materials and with tasks requiring fine finger manipulation.
Radiation, Ionising and Non-Ionising
Radiation is a general term for the processes by which energy is emitted from a radioactive source. The energy emitted is capable of causing considerable harm, depending on its form and the length of exposure.
There are two forms of radiation – ionising and non-ionising. • Ionising Radiation
This includes both the streams of particles emitted by the decay of radioactive substances (alpha- and beta-particles and gamma rays) and X-rays. The energy transmitted is powerful enough to ionise atoms in living tissue, causing chemical changes at the cellular level. At high doses, this can result in massive cell destruction, damage to organs and possibly death. At low doses, it can result in the formation of cancers. If these form in the reproductive organs, it can cause hereditary effects in descendants.
• Non-Ionising Radiation
This form consists of lower energy electromagnetic waves whose energy decreases with increasing wavelength. There is, then, a spectrum of types of non-ionising radiation based upon the wavelength of the energy transmitted. This spectrum, together with the effects on the body, is as follows:
− Ultra-violet radiation has low penetrating power and its effects are confined mainly to the skin and the eyes. Acute effects on the skin are similar to sunburn, whereas chronic effects include premature aging of the skin and skin cancer, although this is highly unlikely to be contracted from occupational sources. The most common effect on the eyes is conjunctivitis, an inflammation of the eye often associated with welding where it is commonly known as “arc eye”.
− Visible radiation is experienced particularly from high intensity beams such as lasers, which can cause serious burns to exposed skin tissue and is particularly dangerous to the eyes.
− Infra-red radiation is emitted from any hot material and can cause reddening of the skin, burns and cataracts in the eyes.
− Microwave radiation generates heat by causing the vibration of liquid molecules within tissues and exposure can, therefore, result in deep-seated burns, particularly to the eyes.
− Radio frequency radiation can cause excessive heating of exposed tissues.
Temperature
The temperature of workrooms should normally be at least 16°C although the general
requirement is that it should be comfortable to work in. There will always be situations where, due to the nature of the work, workers will be exposed to temperatures far above or below what could be considered comfortable. Examples include:
Extreme heat – working with molten metals and in foundries, or hot climates.
Extreme cold – working in cold-stores.
Prolonged exposure to excess heat or cold can lead to fatigue, a general slowing of reactions and a loss of dexterity, affecting both work efficiency and the possibility of making mistakes which can lead to accidents.
Apart from the risk of burns from contact with hot materials, surfaces and equipment, working in very hot environments can cause heat exhaustion, dehydration, heat cramps and heat stroke.
Exposure to extreme cold can lead to a lowering of the body’s deep core temperature, either locally (e.g. in the fingers or toes) where it may cause frostbite or more generally where it can cause hypothermia. These conditions are extremely unlikely in an occupational setting, but lesser effects include shivering, clouded consciousness, pain in the extremities of the body and reduced grip strength and co-ordination. Contact with very cold materials, surfaces and equipment can also cause burns.
Chemical Hazards
There are three basic states of matter: solid, liquid and gas, and each of these states can be in a different form.
Solids
These can be a solid block of, say, wood. If it is put through a sawmill then dust is produced. Dust is a solid.
Similarly, if asbestos is disturbed or damaged, tiny asbestos fibres are produced.
Liquids
We can all visualise the spray coming out of an aerosol of hair spray. This is just a liquid in a different form.
Another form of liquid that we should all be familiar with is a mist.
Gases
These are air-like substances that move freely to fill spaces. Vapour given off from liquids can be put into this category along with gases like hydrogen, carbon dioxide, oxygen, methane, etc.
Fumes can also fit into this category. A true fume is the gas-suspended particulate given off by a process, although the word is often used in a wider sense to incorporate exhaust
emissions.
From what we have said above, you can see that substances can be in different states/forms depending on conditions and how they are being used.
All matter can be in any one of the states depending on circumstances. Temperature and pressure are two factors that can affect the state of a substance.
Temperature
Take water: at low temperatures it is in a solid state, ice. As the temperature rises it melts and becomes water, a liquid. If we raise the temperature sufficiently, the water will start to vaporise and change into steam, a gaseous state.
Pressure
Propane is a good example. At normal atmospheric pressure, propane is a gas. When it is compressed and stored under high pressure inside a cylinder, it becomes a liquid (LPG – liquefied petroleum gas).
As soon as it is released into the atmosphere, it turns into a gas again.
You should realise that whilst chemicals may not pose a significant hazard in one form or state, if that form or state is changed due to the operation that is being carried out or the
surrounding conditions, then the risk posed may also change.
Classification of Chemical Hazards
There are three general classifications of hazards, each of which contain a number of such categories:
