Phosphoric acid, mono- and di-C12-18-(even numbered)-alkyl esters, sodium salts

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

activated sludge respiration inhibition testing

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

RA study and GLP study according OECD Guideline but testing above the water solubilty

Justification for type of information:

Refer to the section 13 for details on the read across justification. The study with the read across substance is considered sufficient to fulfil the information requirements as further explained in the provided endpoint summary.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

yes

Qualifier:

according to guideline

Guideline:

EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)

Deviations:

yes

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

Up to 1 g/L cloudy solution

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Activated sludge from the municipal STP Hildesheim

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

21°C

Nominal and measured concentrations:

0, 100, 180, 320, 580 and 1000 mg/L (nominal) + control

Reference substance (positive control):

yes

Remarks:

Copper(II)sulphate-pentahydrate.

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Duration:

3 h

Dose descriptor:

other: EC20

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Duration:

3 h

Dose descriptor:

other: EC80

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Results with reference substance (positive control):

The positive control gave a 3h EC50 respiration inhibition of 47 and 55%.

Validity criteria fulfilled:

yes

Conclusions:

Based on the results of the read across study, the 3h EC50 (activated sludge, domestic) was determined to be >1000 mg/L (nominal).

Executive summary:

A study was conducted to determine the toxicity to microorganisms of the read across substance, C12 PSE, K+, according to OECD Guideline 209 and EU Method C.11, (activated sludge respiration inhibition testing), in compliance with GLP. Activated sludge (domestic) were exposed to an aqueous dispersion of the test substance at nominal concentrations of 0, 100, 180, 320, 280 and 1000 mg/L. The rate of respiration was determined after 3 hours contact and compared to data for the control. Copper(II)sulphate-pentahydrate was used as positive control and gave a 3h EC50 (respiration inhibition of 47 and 55%). The 3h EC20 and EC80 for the test substance were greater than 1000 mg/L. Based on the results of the read across study, the 3h EC50 (activated sludge, domestic) was determined to be >1000 mg/L (nominal) (Noack, 1991).

Reference 2

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

GLP study according OECD Guideline but testing above the water solubilty

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

yes

Remarks:

different reference substance

Qualifier:

according to guideline

Guideline:

EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)

Deviations:

yes

Remarks:

different reference substance

GLP compliance:

yes

Specific details on test material used for the study:

Appearance: semi-solid (amorphous) - gel

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

Up to 1 g/L cloudy solution

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Activated sludge from the municipal STP Hildesheim

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

21°C

Nominal and measured concentrations:

0, 100, 180, 320, 580 and 1000 mg/L (nominal) + control

Reference substance (positive control):

yes

Remarks:

Copper(II)sulphate-pentahydrate.

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Duration:

3 h

Dose descriptor:

other: EC20

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Duration:

3 h

Dose descriptor:

other: EC80

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Results with reference substance (positive control):

The positive control gave a 3h EC50 respiration inhibition of 47 and 55%.

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the 3h EC50 (activated sludge, domestic) was determined to be >1000 mg/L (nominal).

Executive summary:

A study was conducted to determine the toxicity to microorganisms of the test substance according to OECD Guideline 209 and EU Method C.11, (activated sludge respiration inhibition testing), in compliance with GLP. Activated sludge (domestic) were exposed to an aqueous dispersion of the test substance at nominal concentrations of 0, 100, 180, 320, 280 and 1000 mg/L. The rate of respiration was determined after 3 hours contact and compared to data for the control. Copper(II)sulphate-pentahydrate was used as positive control and gave a 3h EC50 (respiration inhibition of 47 and 55%). The 3h EC20 and EC80 for the test substance were greater than 1000 mg/L. Under the study conditions, the 3h EC50 (activated sludge, domestic) was determined to be >1000 mg/L (nominal) (Noack, 1991).

Description of key information

Based on the results of the read across study, the 3h EC50 of the test substance to activated sludge is considered to be >1000 mg/L (nominal).

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L

Additional information

A study was conducted to determine the toxicity to microorganisms of the read across substance, mono- and di- C12 PSE, K+, according to OECD Guideline 209 and EU Method C.11, (activated sludge respiration inhibition testing), in compliance with GLP. Activated sludge (domestic) were exposed to an aqueous dispersion of the test substance at nominal concentrations of 0, 100, 180, 320, 280 and 1000 mg/L. The rate of respiration was determined after 3 hours contact and compared to data for the control. Copper(II)sulphate-pentahydrate was used as positive control and gave a 3h EC50 (respiration inhibition of 47 and 55%). The 3h EC20 and EC80 for the test substance were greater than 1000 mg/L. Based on the results of the read across study, the 3h EC50 (activated sludge, domestic) was determined to be >1000 mg/L (nominal) (Noack, 1991).

The above read across results are further supported by the absence of microbial inhibition potential of the test substance, mono- and di- C12 -18 PSE, Na+ in the toxicity control group of the ready biodegradation study at a concentration of 19.7 mg/L.