5.1  The purpose of this guide is to assess the ability of air care products to reduce indoor air malodor intensity from a control state. Several experimental hypotheses are possible, depending on the objective of the test. Possible objectives with respective hypotheses are given in Appendix X1.

5.2 Air care products are sold commercially with the intent of providing a means of improving the odor quality of a volume of air, relative to some existing environmental condition. This typically involves the application of an odorous substance into the air space by means of some mechanical or physical mechanisms (for example, air fresheners). When the existing environment includes some undesirable odor source or malodor, reduction of the perception of the malodor is usually accomplished with other odorous substances by masking. This procedure is also applicable to other mechanisms of odor reduction (for example, air filtration).

5.3  Selection of representative malodor sources is of critical importance. The malodor source must be readily available and of a consistent odor quality. A reasonable malodor source should be chemically and aesthetically correct. The experimenter and client must agree upon the appropriateness of a malodor source before further details of the test design are worked out. Experimental variation will be reduced by using uniform malodor sources. Information collected on malodor reduction will thus be more comparable from experiment to experiment and from laboratory to laboratory.

5.4 The procedure recommended can be used for assessment of the malodor efficacy of air care product (for example, air fresheners and air filtration).

5.5 These procedures can be used to assess efficacy against any standard malodor.

5.6 These procedures are applicable in the assessment of any products that reduce the perception of any malodor, regardless of the mode of action.

5.6.1 These procedures are applicable to aerosol/spray and continuous/solid air freshener products, including candles. It should be noted that while aerosol/spray and continuous/solid and candle product evaluations are fundamentally the same, different treatment or measurement techniques may be necessary because of inherent differences in the product delivery systems.

5.6.2 These procedures are applicable to other air care products, including absorption, chemical reaction, and particulate removal.

5.7 This guide is designed for use for product research guidance in product formulation and new product development, and for quality control issues.