Reaction products of 1H-Imidazole-1-ethanol, 4,5-dihydro-, 2-(C11-17 and C17 unsatd. alkyl) derivs. and sodium hydroxide and 2-propenoic acid

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 301 A (new version) (Ready Biodegradability: DOC Die Away Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): non-adapted activated sludge was collected from the sewage plant at Hildesheim (Germany) which treated mostly municipal dewage and hardly industrial chemical wastes
- Laboratory culture: no
- Preparation of inoculum for exposure: the activated sludge was filtered and filtrate was kept in aerobic conditions until test begin
- Pretreatment: no
- Concentration of sludge: not reported
- Initial cell/biomass concentration: 1E07-1E08 CFU/L
- Water filtered: not reported

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

28 d

Details on test conditions:

TEST CONDITIONS
- Composition of medium: mineral nutrient solution acc. to OECD 301A
- Additional substrate: no
- Solubilising agent (type and concentration if used): no
- Test temperature: 21.4-23.4°C (in the course of the test: at each sampling day the temperature was measured)
- pH: 7.42-7.44
- pH adjusted: yes
- Aeration of dilution water: not reported
- Suspended solids concentration: -
- Continuous darkness: yes


TEST SYSTEM
- Culturing apparatus: 2000 mL Erlenmeyer flask
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: inoculum was kept in aerobic conditions until test begin (no further information)
- Measuring equipment: pH-Meter, MULTI 340i, DOC-analysator: MULTI N/C 3000, Analytik, Jena; Thermometer, Huger
- Test performed in closed vessels: not reported

SAMPLING
- Sampling frequency: samples were taken on days 0, 1, 5, 7, 14, 21, and 28
- Sampling method: DOC determination was carried out acc. to Guideline DIN EN 1484 (not further specified)
- Sterility check if applicable: not performed
- Sample storage before analysis: no

CONTROL AND BLANK SYSTEM
- Inoculum blank: performed
- Abiotic sterile control: not reported
- Toxicity control: performed
- Other: functional/procedural control (with Sodium acetate as reference substance) performed

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: degradation rate in toxicity control of a ready biodegradation test

Details on results:

The biodegradation of the reference substance was not inhibited by the test item (degradation of 70% after 14 d, 73% after 28 d).

Validity criteria fulfilled:

yes

Conclusions:

The toxicity of Amphopropionates C12-18 to microorganisms was investigated during a ready biodegradation study. The test item had no inhibitory effect on activated sludge microorganisms at the tested concentration of 100 mg/L.

Executive summary:

The toxicity of Amphopropionates C12-18 (40% a.i.) to microorganisms was investigated during a ready biodegradation study according to OECD guideline 301 A (1992), DOC Die Away Testover a period of 28 days and using an inoculum obtained from activated sludge from a predominantly domestic sewage treatment plant.

Inoculum blank, procedural/functional control with the reference substance Sodium acetate and a toxicity control with 100 mg/L test item and 35 mg/L reference item Sodium acetate were performed.

The reference item degraded normally (95% after 14 d).

The biodegradation in the toxicity control was found to be on average 70% after 14 days of incubation. Thus, according to the test guidelines, the test item had no inhibitory effect on activated sludge microorganisms at the tested concentration of 100 mg/L, as the biodegradation in the toxicity control was higher than 25% within 14 days of incubation.

Reference 2

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test) (1992)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Non-adapted activated sludge was collected from the sewage plant at Hildesheim (Germany) which treats mostly municipal sewage (industrial chemical waste: ca. 30%, referring to BOD) and used as source of the inoculum
- Laboratory culture: no
- Preparation of inoculum for exposure: The activated sludge was filtered with folded filter. The first 200 mL of the filtrate were discarded. The second filtrate effluent from the domestic waste water was used to initiate inoculation.
- Pretreatment: no
- Concentration of sludge: <=30 mg/L suspended solids
- Initial cell/biomass concentration: 1E04 to 1E06 CFU/L
- Water filtered: not reported

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

28 d

Nominal and measured concentrations:

70 mg a.i./L, nominal

Details on test conditions:

TEST CONDITIONS
- Composition of medium: mineral nutrient solution acc. to OECD Guideline 301 F
- Additional substrate: no
- Solubilising agent (type and concentration if used): no
- Test temperature: 20-21°C (temperature was documented by a thermohygrograph)
- pH: at the beginning: 7.68; at the end: 7.56-7.57 (pH was determined at the beginning and at the end of the study period after 28 d
- pH adjusted: no
- Aeration of dilution water: not reported
- Suspended solids concentration: <=30 mg/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: brown glass bottles (incubator)
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: not reported
- Measuring equipment: OxiTop OC110 controller, WTW, OxiTop measuring heads, WTW, Incubator, RUBARTH, pH-Meter 340i, WTW; thermohygrograph
- Test performed in closed vessels: yes

SAMPLING
- Sampling frequency: oxygen consumption was determined continuously from the pressure in the incubation vessels by OxiTOP measuring system at 360 measuring points (every 112 minutes) during the 28 d incubation period.
- Sampling method: oxygen consumption was determined continuously from the pressure in the incubation vessels
- Sterility check if applicable: not reported
- Sample storage before analysis: no


CONTROL AND BLANK SYSTEM
- Inoculum blank: performed
- Abiotic sterile control: not reported
- Toxicity control: performed
- Other: functional/procedural control (Sodium acetate as reference substance) performed

Reference substance (positive control):

no

Duration:

12 d

Dose descriptor:

NOEC

Effect conc.:

70 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: toxicity control in ready biodegradation test

Details on results:

According to the results obtained in the toxicity control the test item was not inhibitory to the inoculum in the concentration used in the test (on average 98.5% biodegradation after 12 d)

Validity criteria fulfilled:

yes

Conclusions:

The toxicity of Amphopropionates C12-18 to microorganisms was investigated during a ready biodegradation study. The test item had no inhibitory effect on activated sludge microorganisms at the tested concentration of 70 mg/L.

Executive summary:

The toxicity of Amphopropionates C12-18 (40% a.i.) to microorganisms was investigated during a ready biodegradation study according to OECD guideline 301 F (1992), Manometric Respirometry Test over a period of 28 days and using an inoculum obtained from activated sludge from a predominantly domestic sewage treatment plant.

Inoculum blank, procedural/functional control with the reference substance Sodium acetate and a toxicity control with 70 mg/L test item and 75 mg/L reference item Sodium acetate were performed.

The reference item degraded normally (100% after 2 days).

The biodegradation in the toxicity control was found to be on average 98.5% after 12 days of incubation. Thus, according to the test guidelines, the test item had no inhibitory effect on activated sludge microorganisms at the tested concentration of 70 mg/L, as the biodegradation in the toxicity control was higher than 25% within 14 days of incubation.

Description of key information

14 d NOEC = 83.7 mg/L (geom. mean from 2 studies:  toxicity control from OECD TG 301 A / OECD TG 301 F; RL1; GLP) 

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

83.7 mg/L

Additional information

To assess the toxicity of Amphopropionates C12-18 to microorganisms, two ready biodegradation studies including a toxicity control are available:

 

The toxicity of Amphopropionates C12-18 (40% a.i.) to microorganisms was investigated during a ready biodegradation study according to OECD guideline 301 F (1992), Manometric Respirometry Test over a period of 28 days and using an inoculum obtained from activated sludge from a predominantly domestic sewage treatment plant.

Inoculum blank, procedural/functional control with the reference substance Sodium acetate and a toxicity control with 70 mg/L test item and 75 mg/L reference item Sodium acetate were performed.

The reference item degraded normally (100% after 2 days).

The biodegradation in the toxicity control was found to be on average 98.5% after 12 days of incubation. Thus, according to the test guidelines, the test item had no inhibitory effect on activated sludge microorganisms at the tested concentration of 70 mg/L, as the biodegradation in the toxicity control was higher than 25% within 14 days of incubation.

 

The toxicity of Amphopropionates C12-18 (40% a.i.) to microorganisms was investigated during a ready biodegradation study according to OECD guideline 301 A (1992), DOC Die Away Test over a period of 28 days and using an inoculum obtained from activated sludge from a predominantly domestic sewage treatment plant.

Inoculum blank, procedural/functional control with the reference substance Sodium acetate and a toxicity control with 100 mg/L test item and 35 mg/L reference item Sodium acetate were performed.

The reference item degraded normally (95% after 14 d).

The biodegradation in the toxicity control was found to be on average 70% after 14 days of incubation. Thus, according to the test guidelines, the test item had no inhibitory effect on activated sludge microorganisms at the tested concentration of 100 mg/L, as the biodegradation in the toxicity control was higher than 25% within 14 days of incubation.

 

For chemical safety assessment the geometric mean of both studies of 83.7 mg/L will be used.