Propanoic acid, 3-mercapto-, C11-14-isoalkyl esters, C13-rich

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

other: see details

Details on inoculum:

supernatant of an activated sludge homogenisate of of the sewage treatment plant Taunusstein-Bleidenstadt (sludge charge from 15.10.1996; treatment of mainly municipal sewage)

Duration of test (contact time):

28 d

Initial conc.:

ca. 13 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

incubation at 20-25°C;
mineral medium; the test item is the only carbon and energy source;
2 negative controls

Reference substance:

benzoic acid, sodium salt

Remarks:

concentration: approx. 20 mg/L TOC

Parameter:

% degradation (CO2 evolution)

Value:

ca. 0 - <= 17

Sampling time:

28 d

Remarks on result:

other: test item assessed to be not readily biodegradable

Parameter:

% degradation (CO2 evolution)

Value:

ca. 0 - <= 28

Sampling time:

35 d

Remarks on result:

other: (time: Day 36 = 35 d of inbubation + 1 d CO2 catchment after acidification)

Details on results:

%Degr. expressed in relation to theoretical CO2 development (TCO2)
According to the test results the test item had to be assessed to be not readily biodegradable.

Results with reference substance:

92% degradation according to CO2 evolution (% of theoretical CO2 development (TCO2)) during 28 d;
threshold limit value for readily biodegradable of >60% degradation was reached after 5 days.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

According to the test results the test item had to be assessed to be not readily biodegradable.

Executive summary:

A laboratory study for assessment of the Ready Biodegradability of the test substance was performed, i.e. the CO2 Evolution Test according to OECD Guideline 301 B. A positive control (reference substance benzoic acid, sodium salt) and 2 negative controls were included in the test program. The validity criteria of the test guideline were met.

According to the test results the test item had to be assessed to be not readily biodegradable.

Description of key information

A laboratory study for assessment of the Ready Biodegradability of the test substance Reaction mass of iso-tridecyl 3-mercaptopropionate and iso-dodecyl 3-mercaptopropionate was performed in the design of a CO2 Evolution Test according to OECD Guideline 301 B. A positive control (reference substance benzoic acid, sodium salt) and 2 negative controls were included in the test program. The validity criteria of the test guideline were met.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable

Type of water:

freshwater

Additional information

According to the test results the test substance Reaction mass of iso-tridecyl 3-mercaptopropionate and iso-dodecyl 3-mercaptopropionate had to be assessed to be not readily biodegradable.