C.1: Comparison of OECD transformation and biodegradation tests

	OECD test 307	OECD test 308	OECD test 309
Matrix	Soil (ay least three types of different soil)	Aquatic sediments and associated waters (at least 2 sediments; different organic carbon content and texture). Fresh and marine if necessary. Not suitable to simulate flowing water	Surface water without particles or sediment and optional additional test with surface sediment (aerobic layers)
Concentration	Maximum dosage on the label of compound that is directly applied to the field should be taken	Maximum dosage on the label of compound that is directly applied to the field should be taken	< 1–100 ug/L
Test method	Biometer‐type flasks or in flow‐through systems	Incubation apparatus (gas flow‐through and biometer‐type systems) in glass containers or Teflon (batch bottles or centrifuge tubes), depending on Kow).	Batch (with stopper or with cotton)
Test time	Max 120 days (if needed, 6–12 months for transformation product monitoring)	Max 100 days, until the degradation pathway and water/sediment distribution pattern are established or when 90% of the test substance has been removed by transformation and/or volatilisation	2 weeks up to 60 days (batch mode) or several months (depending on lag time) in semi‐continuous mode
Compounds to measure	Properties and conditions of soil at start of experiment. Parent compound and TP	Nutrients, properties and conditions of sediment and associated water at start of experiment. Parent compound and TP during experiment (6 points, one concentration).	Nutrients and conditions of surface water at start of experiment. Parent compound and TP if T1/2 > 60 days during experiment (5 points and at least 2 concentrations)
Metabolism/Redox	Aerobic/Anaerobic	Aerobic/Anaerobic	Redox should be measured and should be aerobic
Test conditions	Dark	Dark	Dark, shaking
Test temperature	Controlled temperature (field temp or standard temp of 20°C).	Controlled temperature (10–30°C or standard temp of 20°C)	Controlled temperature (field temp or standard temp of 20–25°C).