Label/standard methodology

In this section, the sensory evaluation methodology is described for each of the most used labels and standards: ICL, GUT, UZ35, Natureplus, VDA 270, SNV 195651, RTS, VDI3882 part 1 and 2, NBN13725 and AFNOR NFX 43-103.

6.3.1. Indoor Climate Label (ICL, Denmark)

Principle: ICL is based on indoor-relevant time values determined for building materials on

the basis of chemical emissions and sensory test. Indoor-relevant time value (chemical emissions) for a product is defined as the necessary time for the slowest emitting individual chemical substance with the lowest indoor relevant odour or irritation threshold to reach half of this threshold value in a fictive standard room. The indoor-relevant time-value based on the sensory evaluations is given as the time (in days) at which the requirements for acceptability and odour intensity are fulfilled. The indoor-relevant time-value is based on the highest time-value of both the chemical and sensory tests. The time-value is given in full days and rounded up to the nearest value, which can be divided by ten.

Panel requirements: The sensory evaluation of the material emission is made by an untrained

panel of at least 20 persons, who rate the air quality by marking the acceptability and odour intensity on continuous scales. The panel members should belong to the age range from 18 to 50 years. Panel members should have a normal olfactory sense. Smoking habits of each member should be noted. The sensory panel should preferably have an equal distribution of both sexes and not more than 40% smokers. The panellists should not suffer from a cold on the days of evaluation.

Panel instruction: Prior to the evaluation of the air quality in the test chambers the members of

the panel should be instructed to:

 refrain from eating garlic or spicy food on the day or the day before the evaluation  refrain from eating or smoking during the last hour prior to evaluation

 have a high personal hygiene and refrain from using strong-smelling cosmetics  wear clothes washed in a neutral detergent.

Each panel member should be carefully instructed how to use the scales in the evaluation form. The panellists should take only one inhalation of the air to be evaluated and report their first impression of acceptability and odour intensity. In case the panellists should evaluate the air quality from more than one test chamber, they should refresh their olfactory sense by breathing clean air for at least 1 minute in between the evaluations. This is to avoid any cross adaptation.

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6.3.2. GUT, Austrian UZ 35, Natureplus label and VDA 270

For carpets, this label includes chemical emissions and odour testing. The olfactory method tries to simulate the odour development at increased temperatures. For this purpose, a sample of 144cm² is thermostated during 15h in a desiccator at 37°C and 50% Hr. After sample conditioning, the team of test persons specially trained (at least 7) for this method individually assesses the resulting odour development and tries to define the type of odour as well as the

intensity and the overall impression. It is the primary objective of such an odour test to ensure a

clear distinction between acceptable new-product odour and unacceptable odour formation. This test is based on the Swiss standard SNV 195651.

6.3.3. The Building Information Foundation RTS (Finland, 2004)

Sensory characterisation of material emissions is carried out using a two-phase sensory test. The sensory assessments are commenced with a naïve sensory panel of at least five members. If the mean acceptability vote of the panel falls outside a certain range, no further sensory testing is needed and the building material belongs either to emission class M1 or M3. If the mean acceptability vote of the panel falls within this certain range, the sensory test shall be repeated with ten more naïve subjects in order to reach a higher accuracy of the evaluation determining the sensory emission class. In this case, the mean acceptability vote is calculated using the values given by all fifteen evaluators each giving two votes. Thus the acceptability calculation is based on 30 evaluations of which the arithmetic mean is calculated.

M1 M2

Sensory evaluation Sensory assessment,

percent of unsatisfied <15% _{(result ≥ +0,1)} <30%

Odour description Not odorous Not significantly

odorous Table 10: Sensory evaluation-RTS method (Finland)

Emission class M3 includes materials whose emissions exceed the values specified for materials in category M2.

Brick, stone, ceramic tile, glass, metal surfaces and wood hold a special status in the classification.

Panel requirements: The sensory testing may be commenced with a panel of five naive

subjects. If the panel acceptability vote of this falls between –0.4 and +0.4 a second round of sensory testing with a panel of ten more members shall be done within one day.

Panel instruction: The panel assesses the acceptability of the air exhausted from the test

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 refrain from eating garlic on the day before sensory assessments

 take a shower in the morning of the assessment day and refrain from using strong-smelling cosmetic products

 wear odourless clothes (no leather jackets etc.)

 abstain from drinking coffee and smoking between sensory assessments and an hour before they begin

This follows the general principles used internationally concerning untrained panels. According to the protocol the panellist is asked to imagine that he/she in the working environment would be exposed to the air similar to that coming out of the chamber.

Procedure:

1. Evaluation of the empty chamber-background acceptability: First, the sensory evaluation