Quaternary ammonium compounds, C18-22 (even numbered) alkyltrimethyl, chlorides; Docosyltrimethylammonium chloride; C18-22 TMAC

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

From August 02, 1990 to September 03, 1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Refer to the Quaternary ammonium salts (QAS) category or section 13 of IUCLID for details on the category justification. The study with the read across substance is considered sufficient to fulfil the information requirements as further explained in the provided endpoint summary.

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

yes

Remarks:

Instead of using 3,5-dichlorophenol as reference (acc. to OECD 209) potassium dichromate was used in a concentration to inhibit respiration of 50%.

GLP compliance:

no

Analytical monitoring:

no

Details on sampling:

Not applicable as nominal test concentrations are evaluated

Vehicle:

no

Details on test solutions:

No further details available

Test organisms (species):

activated sludge, domestic

Details on inoculum:

- Laboratory culture: activated sludge from municipal waste water treatment plant Hildesheim
- Method of cultivation:
- Preparation of inoculum for exposure: washed twice with dechlorinated, autoclaved tap water
- Pretreatment: none
- Initial biomass concentration: 1.251 g/L dry weight

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Post exposure observation period:

Not applicable

Hardness:

Not specified

Test temperature:

22°C

pH:

Not specified

Dissolved oxygen:

Not specified

Salinity:

Not specified

Nominal and measured concentrations:

Nominal: 10 - 18 - 32 - 58 - 100 - 180 mg/L

Details on test conditions:

TEST SYSTEM

- Test vessel:500 mL Erlenmeyer flasks
- Type (delete if not applicable): not specified
- Material, size, headspace, fill volume: 500mL
- Aeration: yes, permanently
- Type of flow-through (e.g. peristaltic or proportional diluter): not specified
- Renewal rate of test solution (frequency/flow rate):not specified
- No. of organisms per vessel:not specified
- No. of vessels per concentration (replicates):1
- No. of vessels per control (replicates):1


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: synthetic water acc. to OECD 209

OTHER TEST CONDITIONS
- Adjustment of pH: not specified
- Photoperiod: not specified
- Light intensity: not specified

Reference substance (positive control):

yes

Remarks:

kaliumdichromat

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

9.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

Respiration rate

Duration:

3 h

Dose descriptor:

other: EC20

Effect conc.:

16 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

Respiration rate

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

43 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

Respiration rate

Duration:

3 h

Dose descriptor:

other: EC80

Effect conc.:

120 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

Respiration rate

Details on results:

No further details available

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: 32 - 58 - 100 mg/ L

No further details available

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the 3 h EC 10 and EC50 (in activated sludge) of the test substance was determined to be 9.5 and 43 mg/L, respectively.

Executive summary:

A study was conducted to determine the toxicity of the read across substance, C20-22 TMAC (active content not specified), to microorganisms according to OECD Guideline 209 (Activated Sludge Respiration Inhibition Test). Approximately 1.251 g/L dry weight of activated sludge (domestic) was exposed to the test substance at nominal concentrations of 10, 18, 32, 58, 100 and 180 mg/L for 3 h. A positive control group (Potassium dichromate) was included in the experiment and gave values within the expected range. Under the study conditions, the 3 h EC10 and EC50 (in activated sludge) of the test substance was determined to be 9.5 and 43 mg/L (nominal), respectively (Hildesheim, 1990). Based on the results of the read across study, similar EC50 values can be expected for the test substance, C18-22 TMAC.

Description of key information

Based on the results of the read across study, the 3 h EC10 and EC50 (in activated sludge) of the test substance, C18-22 TMAC, is considered to be 9.5 and 43 mg/L, respectively (nominal).

Key value for chemical safety assessment

EC50 for microorganisms:

43 mg/L

EC10 or NOEC for microorganisms:

9.5 mg/L

Additional information

A study was conducted to determine the toxicity of the read across substance, C20-22 TMAC (active content not specified), to microorganisms according to OECD Guideline 209 (Activated Sludge Respiration Inhibition Test). Approximately 1.251 g/L dry weight of activated sludge (domestic) was exposed to the test substance at nominal concentrations of 10, 18, 32, 58, 100 and 180 mg/L for 3 h. A positive control group (Potassium dichromate) was included in the experiment and gave values within the expected range. Under the study conditions, the 3 h EC10 and EC50 (in activated sludge) of the test substance was determined to be 9.5 and 43 mg/L (nominal), respectively (Hildesheim, 1990). Based on the results of the read across study, similar EC50 values can be expected for the test substance, C18-22 TMAC, for toxicity to microorganisms.