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 water and sediment: simulation tests

Administrative data

Endpoint:

biodegradation in water: sediment simulation testing

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

July 1982- May 1983

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:

1983

Report date:

1983

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The study was carried out to investigate the degradation of cyhalothrin in two river waters with their sediments present and with exposure to normal daylight. Quartz flasks, which are transparent to the UV and visible radiation in sunlight, were used to contain these river waters and their respective sediments. Radiolabelled cyhalothrin was added to the water/sediment mixtures and the flasks were exposed to sunlight for periods up to 32 days.
In order to distinguish between photodegradation and other degradative processes, some similarly prepared flasks were wrapped in aluminium foil and maintained alongside the irradiated flasks.
Traps were attached to all of the flasks to allow the measurement of any volatile radioactive compounds which might be formed.
Flasks were analysed at intervals up to 32 days and the results obtained are given in this report.

GLP compliance:

no

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:

14C-cyclopropane labelled cyhalothrin was applied, at the nominal application rate of 0.9 mg/l, to two natural river water and associated sediment systems and exposed to daylight for up to 32 days. In order to distinguish between photodegradation and other degradative processes, additional systems were prepared, in which light was totally excluded. The water:sediment test systems were set up in quartz flasks and a flow-through system enabled the trapping and quantification of volatile products. The water in each flask was aerated for 3 minutes each day, to ensure the longevity of the biological activity of the test systems. The sediment types used in this study are summarised below:

Location	pH	Soil Type
Whitewater	8.05	Silty
Pang	7.8	Stony

Under dark conditions, degradation of cyhalothrin was fairly slow (80% unchanged after 32 days), however, when exposed to sunlight, cyhalothrin degraded more rapidly, with a half-life of approximately 20 days. Significantly, the rate at which the parent compound was lost from the aqueous phase, was much faster than its rate of degradation in the whole water:sediment system. Indeed this result is unsurprising, given the strong adsorption to soil. The primary route of degradation in light of the 14C-cyclopropane-labelled cyhalothrin proceeded by ester hydrolysis, yielding the corresponding acids (Compound Ia and Ib), which represented up to 47.3% of the applied material after 32 days. Unextracted radioactivity reached levels of approximately 12% after 32 days. The remainder of the radioactivity after 32 days consisted of two unidentified compounds (up to 1.2%), radioactivity remaining at the origin or "streaked" over the length of chromatograms (up to 7%) and radioactivity remaining in water after partition with dichloromethane (up to 7.8%).