Fatty acids, C16-18 (even numbered), ammonium salts

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

December 28, 1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 301 C(Ready Biodegradability: Modified MITI Test (I))

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

not specified

Test organisms (species):

activated sludge

Details on inoculum:

- Initial biomass concentration: 30 mg/L

Test type:

other: Readily biodegradability

Water media type:

freshwater

Limit test:

no

Total exposure duration:

28 d

Details on test conditions:

TEST SYSTEM
Test equipment: Standard type.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): BOD and test item concentration by GC.

TEST CONCENTRATIONS
- Test concentrations: 100 mg/L.

Reference substance (positive control):

not specified

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Test item sodium stearate was readily biodegradable under test conditions.

BOD (28 days): 83% degradation

Test material analysis by GC (28 days): 100% degradation.

Validity criteria fulfilled:

not specified

Conclusions:

The NOEC for microorganism toxicity of the test item sodium stearate was determined to be 100 mg/L under test conditions.

Executive summary:

Based on the Readily Biodegradability test performed with sodium stearate according to OECD Guideline 301 C, where the substance was found to be readily biodegradable at 100 mg/L (28 days), the NOEC for microorganism toxicity is determined to be 100 mg/L since the compound degrades well.

Reference 2

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

December 16, 1997

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 301 C(Ready Biodegradability: Modified MITI Test (I))

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

not specified

Test organisms (species):

activated sludge

Details on inoculum:

- Initial biomass concentration: 30 mg/L

Test type:

other: Readily biodegradability

Water media type:

freshwater

Limit test:

no

Total exposure duration:

28 d

Details on test conditions:

TEST SYSTEM
Test equipment: Standard type.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): BOD and test item concentration by GC.

TEST CONCENTRATIONS
- Test concentrations: 100 mg/L.

Reference substance (positive control):

not specified

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Test item sodium stearate was readily biodegradable under test conditions.

BOD (28 days): 51% degradation

Test material analysis by GC (28 days): 73% degradation.

In a parallel inherent degradation test was performed for 4 weeks in an open system (test substance: 30 mg/L, activated sludge: 100 mg/L) and the % degradation was determined to be 95% (test item measured by GC)

Validity criteria fulfilled:

not specified

Conclusions:

The NOEC for microorganism toxicity of the test item docosanoic acid was determined to be 100 mg/L under test conditions.

Executive summary:

Based on the Readily Biodegradability test performed with docosanoic acid according to OECD Guideline 301 C, where the substance was found to be readily biodegradable at 100 mg/L (28 days), the NOEC for microorganism toxicity is determined to be 100 mg/L since the compound degrades well.

Reference 3

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Principles of method if other than guideline:

No data on experimental method.

GLP compliance:

not specified

Remarks:

(no data on GLP)

Analytical monitoring:

not specified

Vehicle:

yes

Details on test solutions:

15% propylen glycol and 34-37% water

Test organisms (species):

Pseudomonas putida

Test type:

not specified

Water media type:

freshwater

Total exposure duration:

17 h

Duration:

17 h

Dose descriptor:

EC10

Effect conc.:

> 580 mg/L

Key result

Duration:

17 h

Dose descriptor:

EC50

Effect conc.:

> 890 mg/L

Duration:

17 h

Dose descriptor:

other: EC90

Effect conc.:

> 1 200 mg/L

The 17 hour exposure EC10, EC50 and EC90 for ammonium propionate to Pseudomonas putida were determined to be >580 mg/L, >890 mg/L and >1200 mg/L.

Validity criteria fulfilled:

not specified

Conclusions:

The 17 hour exposure EC10, EC50 and EC90 for ammonium propionate to Pseudomonas putida were determined to be >580 mg/L, >890 mg/L and >1200 mg/L.

Executive summary:

The 17 hour exposure EC10, EC50 and EC90 for ammonium propionate to Pseudomonas putida were determined to be >580 mg/L, >890 mg/L and >1200 mg/L.

Reference 4

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: No guideline was followed. No data on GLP.

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: The inhibitory effect of sodium palmitate on the oxygen uptake rate of activated sludge was investigated by the use of the oxygen electrode method.

GLP compliance:

not specified

Test organisms (species):

activated sludge

Test type:

not specified

Water media type:

freshwater

Total exposure duration:

96 h

Key result

Duration:

96 h

Dose descriptor:

IC50

Effect conc.:

> 2 500 mg/L

Validity criteria fulfilled:

not specified

Conclusions:

The inhibitory effect of sodium palmitate on the oxygen uptake rate of activated sludge was investigated by the use of the oxygen electrode method. The IC50 -96h was determined to be >2500 mg/L.

Executive summary:

The inhibitory effect of sodium palmitate on the oxygen uptake rate of activated sludge was investigated by the use of the oxygen electrode method. The IC50 -96h was determined to be >2500 mg/L.

Description of key information

Weight of evidence: Based on the experimental results obtained with the analogue substance, the weight of evidence approach was applied and the NOEC for microorganism toxicity for the substance Fatty acids, C16-18 (even numbered), ammonium salts was determined to be 100 mg/L (worst case assumption).

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

100 mg/L

Additional information

Weight of Evidence Approach (see rationale attached in IUCLID5 Section 13):

According to Verschueren K (2009), the 17 hour exposure EC10, EC50 and EC90 for ammonium propionate to Pseudomonas putida were determined to be >580 mg/L, >890 mg/L and >1200 mg/L.

In a study reported by Mihara Y et al. (1992), the inhibitory effect of sodium palmitate on the oxygen uptake rate of activated sludge was investigated by the use of the oxygen electrode method. The 96h-IC50 was determined to be >2500 mg/L.

Based on the Readily Biodegradability test performed by MITI according to OECD 301 C, sodium stearate was exposure to activated sludge for 28 days and the substance was found to be readily biodegradable at a concentration of 100 mg/L. Therefore, the NOEC for microorganism toxicity is determined to be 100 mg/L since the compound degrades well.

In the same way a Readily Biodegradability test was performed by MITI according to OECD 301 C on docosanoic acid. Activated sludge was exposed to the test item for 28 days and the substance was found to be readily biodegradable at a concentration of 100 mg/L. Therefore, the NOEC for microorganism toxicity is determined to be 100 mg/L since the compound degrades well.

Taking into account the available experimental results, the weight of evidence approach was applied and the NOEC for toxicity to microorganisms for the substance Fatty acids, C16 -18 (even numbered), ammonium salts was determined to be 100 mg/L (based on the worst case assumption.