3-(2-dodecenyl)succinic anhydride

Toxicity to microorganisms

Description of key information

The toxicity of tetrapropenyl succinic anhydride to micro-organisms was evaluated in an activated sludge respiration inhibition test conducted on tetrapropenyl succinic anhydride in accordance with OECD Guideline 209, by read-across based on a grouping of substances (category approach).

Key value for chemical safety assessment

EC50 for microorganisms:

800 mg/L

EC10 or NOEC for microorganisms:

100 mg/L

Additional information

The study “Activated Sludge, Respiration Inhibition Screening Test on Test Substance OS-18230” (Kung, Ricerca, 1995), in which tetrapropenyl succinic anhydride was evaluated based on OECD Guideline Method 209, was identified as the key study,by read-across based on a grouping of substances (category approach). The activated sludge obtained from a domestic sewage treatment plant was used as the microbial source to test the toxicity of the substance. The effects of the test substance on micro-organisms was determined by measuring the microbial respiration rate under defined conditions in the presence of different concentrations of the test substance (1, 10, 100, 1,000 and 10,00 mg/L). The test substance was determined to be non-inhibitory to microbial respiration at concentrations lower than 100 ppm (NOEC estimated at 100 mg/L). However, the test substance was shown to inhibit microbial respiration at higher concentrations with an estimated EC₅₀of 800 ppm (mg/L); this EC₅₀value will be used to represent the substance, by read-across based on a grouping of substances (category approach).

A category approach is used for the hazard assessment of several endpoints. The hypothesis for the category of C8-12 Alkenyl Succinic Anhydrides is that data can be read-across among members of the category, because the properties and behaviours of category members are similar, based on common functional groups, similar breakdown products, and demonstration of a constant pattern associating the potency of properties with the various carbon chain lengths. Functional groups include a dihydro-2,5-furandione cyclic anhydride ring, a carbon chain of length 8 -12 carbons, and a single carbon-carbon double-bond within the carbon chain. The primary functional group associated with toxicity is the succinic anhydride moiety, which is quickly hydrolysed to form a butanedioic acid. A constant pattern may also be displayed in acute toxicity, dermal irritancy and biodegradation, with the lowest carbon chain length (C8) displaying the highest activity. Irritation, toxicity and degradation potential diminish with increasing carbon chain length. Read-across among the category members is substantiated by the common behaviour in physico-chemical and toxicity behaviours, as provided in the Chemical Category Report Format (CCRF) attached to the IUCLID file. It is adequate to fulfil the information requirements of Annex IX, to be the basis for classification and labelling decisions, and for risk assessment.