Reaction mass of (R)-cyano(3-phenoxyphenyl)methyl rel-(1R,3R)-3-((1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate and (R)-cyano(3-phenoxyphenyl)methyl rel-(1S,3S)-3-((1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate

Biodegradation in soil

Administrative data

Endpoint:

biodegradation in soil: simulation testing

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

January 1981-June 1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Report date:

1981

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

In the study the fate of 14C-cyhalothrin in soil under laboratory conditions has been examinated.
14c- cyclopropane labelled cyhalothrin was used in this experiment in order to determine the fate of cyhalothrin and those metabolites which retain the cyclopropane 14C-atom of the molecule. However, with this position of radiolabelling, the fate of any metabolites of the a-cyano-3-phenoxybenzyl alcohol moiety could not be determined once the ester linkage of the molecule had been cleaved. This is not a problem since the fate in soil of the 'alcohol' moieties of many other synthetic pyrethroids is well established. Several of the compounds which have been studies are, like cyhalothrin, esters of a-cyano-3-phenoxybenzyl alcohol. The cleaved 'alcohol' moiety of cyhalothrin will therefore behave in exactly the same way as this group when it is generated by the cleavage of these other pyrethroid percursors.

GLP compliance:

no

Test type:

laboratory

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of (R)-cyano(3-phenoxyphenyl)methyl rel-(1R,3R)-3-((1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate and (R)-cyano(3-phenoxyphenyl)methyl rel-(1S,3S)-3-((1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate

EC Number:

932-389-6

Molecular formula:

C23H19ClF3NO3

IUPAC Name:

Reaction mass of (R)-cyano(3-phenoxyphenyl)methyl rel-(1R,3R)-3-((1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate and (R)-cyano(3-phenoxyphenyl)methyl rel-(1S,3S)-3-((1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate

Radiolabelling:

yes

Applicant's summary and conclusion

Conclusions:

The study is considered to be reliable with restrictions. The results are sufficiently detailed and unambiguous as to be adequate for risk assessment, classification and labeling.

Executive summary:

A sandy loam and a coarse loamy sand soil were incubated with formulated¹⁴C-cyclopropane labelled cyhalothrin at a high rate (100μg a.i./g of moist soil) under aerobic conditions in the laboratory. Little degradation of the applied pesticide occurred during a 10 week period. Dilution (10x) of the treated sandy loam soil with fresh soil after 3 weeks incubation increased the degradation rate such that, after a further 7 weeks incubation, only 59% of the recovered pesticide remained unchanged and 7.9% has been evolved as¹⁴CO2. A fresh sample of the sandy loam soil was also treated at a very low rate (0.59μg a.i./g of moist soil) with non-formulated¹⁴C- cyhalothrin. Degradation was then rapid wi til only 28% of the recovered radioactivity present as cyhalothrin after a 5 week incubation period, with 30.1% evolved as¹⁴C02.The degradation products were shown to include the cyclopropane carboxylic acid hydrolysis product of cyhalothrin. It is concluded that high residues of cyhalothrin in soil are likely to degrade only slowly, but since the compound has a low mobility in soil the residue will remain localised. However, if contaminated soil is dispersed in the environment, the compound is likely to degrade readily.