Registration Dossier

Ecotoxicological information

Toxicity to microorganisms

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The harmful threshold (24 h) of a C14-17 chlorinated paraffin (41% chlorinated) to anaerobic bacteria from a domestic waste water treatment plant using the ETAD fermentation method was reported as 800 mg/L (considerd the 24h NOEC for this study). The respiration of microorganisms in activated sludge from a municipal sewage treatment plant over 3 h was unaffected by the presence of a C14-17 chlorinated paraffin (52% chlorinated) at concentrations of up to 2000 mg/L (considered the 3h NOEC for this study).

Key value for chemical safety assessment

Additional information

In an unpublished study (with only limited reporting in the final RAR), the toxicity of a C14-17 chlorinated paraffin (41% chlorinated) to anaerobic bacteria from a domestic waste water treatment plant has been examined using the ETAD fermentation tube method. The harmful threshold (24 hour; no further details given) was reported as 800 mg/l (considered the NOEC for this study) (Hoescht, 1976). The NOEC of 800 mg/L reported in this study will be used for the derivation of the PNEC.

In another unpublished study (with only limited reporting in expert reviews), the effect of a C14-17 chlorinated paraffin (52% chlorinated) on the respiration of micro-organisms in activated sludge recovered from a municipal sewage plant was examined in a study apparently based on OECD Guideline 209. No inhibition of respiration was seen over a 3 h period when sludge was exposed to the test substance, emulsified in water with nonylphenol ethoxylate (0.5 g/L), at concentrations up to 2000 mg/L (considered the NOEC for this study) (Hoescht, 1985 cited in BUA, 1992 and EU, 2005).