Reaction mass of tridecanal and 2-methyldodecanal and pentadecanal and 2-methyltetradecanal

Biodegradation in water: screening tests

Description of key information

n/i-C13 -C15 –aldehydes were readily biodegradable (65% at 21 days; 10-day window met) in an OECD TG 310 assay under GLP conditions. 

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

n/i-C13 -C15 –aldehydes (23.6 mg/L), a mixture of n/iso C₁₃and C₁₅aldehydes, was tested for ready biodegradation in an OECD TG 310 assay under GLP conditions. The formation of carbon dioxide was monitored up to 28 days by analyzing the inorganic carbon (IC) which was formed from the dissolved and gaseous carbon dioxide contained in the test vessel by the addition of NaOH. The IC found was corrected for the endogenous carbon dioxide of the inoculum control. Co-incubation with 1-octanol (25.4 mg/L) was made to examine the toxicity of the n/i-C13 -C15 –aldehydes. The inoculum was obtained from a municipal wastewater treatment plant.

The results indicate that the degree of biodegradation was 65% under the test conditions within the 28-day period. The pass-level for ready biodegradation, i.e. a result of ≥60% within a 10-day window within the 28-day test period, was reached. The biodegradation of 1-octanol (25.4 mg/L in the test) was not inhibited by the n/i-C13 -C15 –aldehydes at 23.6 mg/L, i.e. there was no toxicity to microorganisms at this concentration.

 

In conclusion, n/i-C13 -C15 –aldehydes were shown to be readily biodegradable in a valid GLP guideline test which is considered to be suitable for assessment (Harlan, 2011).

This result is supported by the earlier observation that n/i-C13 -C15 –aldehydes are biodegradable (>60% BOD; 10 -d window not passed). However, this study was devaluated because of methodological uncertainties (Hoechst, 1995).