OECD 301 (1992) test guideline presents six methods (i.e., A-F) that permit the screening of chemicals for ready biodegradability in an aerobic aqueous medium.

Method 301 C modified MITI test is based on measuring the oxygen uptake of inoculated microorganisms in well mixed suspension consisting of the test substance and mineral solution over a period of 28 days in a darkened, enclosed respirometer at 25 ± 1 ^oC. Biodegradation is expressed as the percentage oxygen uptake (corrected for blank uptake) of the theoretical uptake.

Method 301 F refers to manometric respirometry test. The consumption of oxygen is determined either by measuring the quantity of oxygen required to maintain constant gas volume in the respirometer flask, or from the change in volume or pressure in the apparatus.

BPC Blue is a fully automated biodegradability testing system suitable for OECD 301C and 301F. Utilising an in-situ carbon dioxide absorption kit, BPC Blue functions as a closed-respirometer for continuous and on-line measurement of oxygen consumption or depletion caused by aerobic respiration of microorganisms. The instrument is suitable for all test protocols which the measurement principle is based on oxygen demand measurement.