1,6-Octadien-3-ol, 3,7-dimethyl-, acid-isomerized

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Remarks:

for representative component of the "monoterpene ether" constituent group

Adequacy of study:

key study

Study period:

2 June 1992 - 30 June 1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other:

Principles of method if other than guideline:

Absence of microbial toxicity can be inferred from biodegradation studies. If a compound degrades well in a ready biodegradability test, this concentration can be used as a NOEC value. The ready biodegradability of D-limonene was assessed in a sealed CO2 ready biodegradability test at a test concentration of 10 mg/L (organic carbon). The level of biodegradation achieved after 28 days was 71.4% and the 10-day window was fulfilled. Thus D-Limonene was shown to be readily biodegradable.

GLP compliance:

yes

Specific details on test material used for the study:

D-Limonene, Purity 95%

Details on inoculum:

Secondary effluent from an unacclimatised activate sludge plant

Nominal and measured concentrations:

10 mg/L

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Remarks on result:

other: representative for unsaturated monoterpene hydrocarbon compoennts of the regiestered substance.

Details on results:

The ready biodegradability of D-limonene was assessed in a sealed CO2 ready biodegradability test at a test concentration of 10 mg/L (organic carbon). The level of biodegradation achieved after 28 days was 71.4% and the 10-day window was fulfilled. Thus D-Limonene is readily biodegradable and the absence of microbial toxicity inferred.

Conclusions:

The ready biodegradability of D-limonene was assessed in a sealed CO2 ready biodegradability test at a test concentration of 10 mg/L (organic carbon). The level of biodegradation achieved after 28 days was 71.4% and the 10-day window was fulfilled. Based on these results D-Limonene is considered readily biodegradable and the absence of toxicity to inoculum inferred. Thus the test concentration of 10 mg/L can be considered the NOEC for toxicity to STP micrrorganisms.

D-limonene has been used to represent the "unsaturated monoterpene hydrocarbons" assessment entity for the purposes of the environmental risk assessment of the registered multi-constituent substance. The rationale for using this substance is provided in the biodegradation endpoint.

Description of key information

For the "unsaturated monoterpene hydrocarbon" group, the representative substance Limonene was shown to readily biodegradable in a test performed at 10mg/L. Thus this concentration has been used to represent the NOEC for this group.

 

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

10 mg/L