Sorbitan monostearate, ethoxylated

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from peer reviewed journal

Justification for type of information:

Data is from peer reviewed journal

Qualifier:

according to guideline

Guideline:

other: Refer below

Principles of method if other than guideline:

The effect of test chemical on methanogenesis and the microbial reductive dechlorination of hexachlorobenzene (HCB) was examined using three anaerobic, HCB-dechlorinating mixed cultures, one glucose fed and two lactate fed, that were derived from contaminated estuarine sediments. The two lactate-fed cultures differed significantly in their metabolic activity, especially with respect to the rate and extent of HCB reductive dechlorination. The objective of the study was to screen and select biologically compatible surfactants for use in subsequent research on surfactant-enhanced bioavailability of sorbed-phase chlorinated organic contaminants.

GLP compliance:

no

Analytical monitoring:

yes

Vehicle:

not specified

Test organisms (species):

anaerobic microorganisms

Details on inoculum:

using contaminated estuarine sediments as inoculum.

Test type:

static

Water media type:

freshwater

Total exposure duration:

82 d

Test temperature:

22° C

Nominal and measured concentrations:

10 to 1000 mg/L.

Details on test conditions:

The mixed cultures were developed at 22° using contaminated estuarine sediments as inoculum. One culture received glucose and the other two lactate as the carbon source. One of the lactate-fed cultures exhibited slow dechlorination activity while the other actively dechlorinated HCB. Reductive
dechlorination assays were performed at surfactant concns. ranging from 10 to 1000 mg/L.

Reference substance (positive control):

not specified

Key result

Duration:

82 d

Dose descriptor:

EC50

Effect conc.:

50 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: dechlorination rate

Remarks on result:

other: Other details not known

Details on results:

The effect of test chemical on the reductive dechlorination of hexachlorobenzene (HCB) was examimed using three anaerobic HCB-dechlorinating enriched cultures.

Validity criteria fulfilled:

not specified

Conclusions:

Based on the above effects observations, the EC was determine to be 50 mg/l.

Executive summary:

The effect of test chemical on methanogenesis and the microbial reductive dechlorination of hexachlorobenzene (HCB) was examined using three anaerobic, HCB-dechlorinating mixed cultures, one glucose fed and two lactate fed, that were derived from contaminated estuarine sediments. The two lactate-fed cultures differed significantly in their metabolic activity, especially with respect to the rate and extent of HCB reductive dechlorination. The objective of the study was to screen and select biologically compatible surfactants for use in subsequent research on surfactant-enhanced bioavailability of sorbed-phase chlorinated organic contaminants. The effect of test chemical on the reductive dechlorination of hexachlorobenzene (HCB) was examimed using three anaerobic HCB-dechlorinating enriched cultures. Based on the above effects observations, the EC was determine to be 50 mg/l.

Description of key information

The effect of test chemical on methanogenesis and the microbial reductive dechlorination of hexachlorobenzene (HCB) was examined using three anaerobic, HCB-dechlorinating mixed cultures, one glucose fed and two lactate fed, that were derived from contaminated estuarine sediments. The two lactate-fed cultures differed significantly in their metabolic activity, especially with respect to the rate and extent of HCB reductive dechlorination. The objective of the study was to screen and select biologically compatible surfactants for use in subsequent research on surfactant-enhanced bioavailability of sorbed-phase chlorinated organic contaminants. The effect of test chemical on the reductive dechlorination of hexachlorobenzene (HCB) was examimed using three anaerobic HCB-dechlorinating enriched cultures. Based on the above effects observations, the EC was determine to be 50 mg/l.

Key value for chemical safety assessment

EC50 for microorganisms:

50 mg/L

Additional information

The effect of test chemical on methanogenesis and the microbial reductive dechlorination of hexachlorobenzene (HCB) was examined using three anaerobic, HCB-dechlorinating mixed cultures, one glucose fed and two lactate fed, that were derived from contaminated estuarine sediments. The two lactate-fed cultures differed significantly in their metabolic activity, especially with respect to the rate and extent of HCB reductive dechlorination. The objective of the study was to screen and select biologically compatible surfactants for use in subsequent research on surfactant-enhanced bioavailability of sorbed-phase chlorinated organic contaminants. The effect of test chemical on the reductive dechlorination of hexachlorobenzene (HCB) was examimed using three anaerobic HCB-dechlorinating enriched cultures. Based on the above effects observations, the EC was determine to be 50 mg/l.