1,3-Oxathiolane-2-carboxylic acid, 5-hydroxy-, (1R,2S,5R)-5-methyl-2-(1-methylethyl)cyclohexyl ester, (2R,5R)-

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14.08.2006 to 03.11.2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Menthyloxathiolane

IUPAC Name:

Menthyloxathiolane

Constituent 2

Reference substance name:

(1R,2S,5R)-2-isopropyl-5-methylcyclohexyl (2R,5R)-5-hydroxy-1,3-oxathiolane-2-carboxylate

EC Number:

604-569-1

Cas Number:

147126-62-3

Molecular formula:

C14H24O4S

IUPAC Name:

(1R,2S,5R)-2-isopropyl-5-methylcyclohexyl (2R,5R)-5-hydroxy-1,3-oxathiolane-2-carboxylate

Test material form:

solid: compact

Study design

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

The activated sludge used for this study was washed by centrifugation and the supernatant liquid phase was decanted. The solid material was re-suspended in tap water and again centrifuged. This procedure was repeated twice. An aliquot of the final sludge suspension was weighed, dried
and the ratio of
wet sludge to its dry weight was determined. Based on this
ratio, calculated aliquots of washed sludge suspension, corresponding
to 1.5 g dry material per litre were mixed with test
water (see 6.5) and then aerated until use.
The washed activated sludge was feed and aerated according
to the test guideline and used one day later for the experiment.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

51 mg/L

Details on study design:

Surrounding Type: Climatic chamber
Temperature: 22 °C
Light Conditions: Darkness
pH-Value of Test Solutions: 7.6 (measured at the start of the test) 7.7- 7.9 (measured at the end of the test)

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

% Degradation 1

Parameter:

% degradation (O2 consumption)

Value:

44

Sampling time:

14 d

% Degradation 2

Parameter:

% degradation (O2 consumption)

Value:

51

Sampling time:

28 d

Applicant's summary and conclusion

Conclusions:

Based on ThODNH4. the degradation rate of menthyloxathiolane reached 44% (mean) after 14 days of incubation and 51% (mean) after 28 days of incubation. The degradation rate of menthyloxathiolane did not reach 60 % within the 10-day window and after 28 days of incubation. Therefore,
menthyloxathiolane is not considered to be readily biodegradable.