Abstract: Foam extinguishing agent has been produced, stored and used in large quantities due to its excellent fire extinguishing performance, but it has attracted much attention due to the inevitable environmental burden in the whole life cycle of the product. In order to use foam extinguishing agent more safely and scientifically and improve the ecological friendly properties of the product, its biodegradability is effectively evaluated. In this paper the characteristics and applicability of the classic ready biodegradability test methods were compared, and the method operation was optimized and adjusted in combination with the product characteristics of foam extinguishing agent. The method validation was carried out with four foam extinguishing agent products, AFFF, AFFF/AR, FP and MJAP as representatives. In response to the problem of poor repeatability of biodegradation test results, repeated tests were conducted on each sample, and the classic quartile statistical method was used for data validity analysis. The principle of removing outlier data was obtained, which significantly improved the scientificity of biodegradation test data analysis and was conducive to the optimization and improvement of test.

Key words: foam extinguishing agent, ready biodegradability, robust statistic method, quartile division