4-vinylpyridine

Biodegradation in water and sediment: simulation tests

Description of key information

Biodegradation simulation testing of 4-vinylpyridine in sediments is waived. According to Regulation (EC) No.1907/2006, Annexes IX and X, Column 2, further testing for ultimate biodegradation in sediment shall be proposed if the Chemical Safety Assessment according to Annex 1 indicates the need to investigate further the degradation of the substance or its degradation products.  Additional testing need not be conducted if direct or indirect exposure of the substance in the compartment is unlikely.  In aqueous environments, autopolymerisation of the 4VP will be promoted by water absorption, dilution of the polymerisation inhibitor and the potential interaction with other chemicals that may act as initiators of polymerisation. Any 4VP that does not polymerise is soluble in water based on the water solubility (29,100 mg/L at 20 °C).  From aqueous solution, 4VP will partition to the atmosphere (based on its Henry’s Law Constant of 0.00000362 atm m³/mol at 25 °C and 1 hPa), or partition to sediments (based on its Koc of 219.5 L/kg).  Residual 4VP in soil or sediments is expected to undergo primary biodegradation in a timeframe of days to weeks (based on the timeframe predicted by BIOWIN 4). The compound does not have the potential to sorb strongly onto sediment or soil.  According to Annex I, if the risk characterisation ratio in the chemical safety assessment is below 1.0, the risks are considered controlled.   In the chemical safety assessment of this substance, the risk characterization ratio is below 1, and so there is no need to investigate further the degradation of this substance.