Formaldehyde, oligomeric reaction products with 3-aminomethyl-3,5,5-trimethylcyclohexylamine and 4-tert-butylphenol

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 March 2018 - 19 April 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1992

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3-aminomethyl-3,5,5-trimethylcyclohexylamine

EC Number:

220-666-8

EC Name:

3-aminomethyl-3,5,5-trimethylcyclohexylamine

Cas Number:

2855-13-2

Molecular formula:

C10H22N2

IUPAC Name:

3-(aminomethyl)-3,5,5-trimethylcyclohexanamine

Constituent 2

Reference substance name:

4-tert-butylphenol

EC Number:

202-679-0

EC Name:

4-tert-butylphenol

Cas Number:

98-54-4

Molecular formula:

C10H14O

IUPAC Name:

4-tert-butylphenol

Constituent 3

Reference substance name:

2-(((5-amino-1,3,3-trimethylcyclohexyl)methylamino)methyl)-4-tert-butylphenol

Molecular formula:

C21H36N2O

IUPAC Name:

2-(((5-amino-1,3,3-trimethylcyclohexyl)methylamino)methyl)-4-tert-butylphenol

Test material form:

liquid: viscous

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, predominantly domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): A mixed population of sewage treatment micro-organisms was obtained on 19 March 2018 from the final effluent stage of the Severn Trent Water Plc sewage treatment plant at Loughborough, Leicestershire, UK, which treats predominantly domestic sewage.
- Preparation of inoculum for exposure: The sample of effluent was filtered through coarse filter paper (first approximate 200 mL discarded) and maintained on aeration in a temperature controlled room at temperatures of between 16 and 21 ºC prior to use.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: mineral medium as recommended in the OECD Guidelines
- Solubilising agent (type and concentration if used): acetone
A nominal amount of test item (1000 mg) was dissolved in 10 mL of acetone to give a 1000 mg/10 mL solvent stock solution. An aliquot (500 μL) of this solvent stock solution was dispensed onto a filter paper and the solvent allowed to evaporate to dryness for approximately 15 minutes. The filter paper was dispersed in approximately 350 mL of mineral medium with the aid of high shear mixing (approximately 7500 rpm, 5 minutes) prior to addition of inoculum. The volume was then adjusted to 500 mL to give a final concentration of 100 mg/L. The volumetric flask containing the solvent stock solution was inverted several times to ensure homogeneity of the solution.
- Test temperature: 20 - 22 ºC
- pH: 7.6 at test start
- pH adjusted: no
- Continuous darkness: diffuse light


TEST SYSTEM
- Culturing apparatus: CES Multi-Channel Aerobic Respirometer
- Number of culture flasks/concentration: 3

SAMPLING
- Sampling frequency: daily

CONTROL AND BLANK SYSTEM
Three replicate bottles containing inoculated mineral medium to act as the inoculum control plus a filter paper.
Two replicate bottles containing inoculated mineral medium plus a filter paper and the reference item, aniline, at a concentration of 100 mg/L.
Two replicate bottles containing the test item on filter paper at a concentration of 100 mg/L in inoculated mineral medium plus the reference item, aniline, at a concentration of 100 mg/L to act as toxicity control vessels.

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

% Degradation 1

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

% Degradation 2

Parameter:

% degradation (O2 consumption)

Remarks:

toxicity control

Value:

32

Sampling time:

14 d

Details on results:

The test item attained 0% biodegradation after 28 days, calculated from the oxygen consumption values, and therefore cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No. 301F.
The toxicity control attained 32% biodegradation after 14 days and 33% biodegradation after 28 days thereby confirming that the test item was not toxic to the sewage treatment micro-organisms used in the test.

BOD5 / COD results

Results with reference substance:

Aniline (procedure control) attained 67% biodegradation after 14 days and 76% biodegradation after 28 days thereby confirming the suitability of the inoculum and test conditions.

Any other information on results incl. tables

The mean BOD of the inoculated mineral medium (control) was 26.45 mg O2/L after 28 days and therefore satisfied the validation criterion given in the OECD Test Guidelines.

The pH of the inoculated test item vessels on Day 28 were 7.8 and hence satisfied the validation criterion given in the OECD Test Guidelines.

The difference between extremes of replicate BOD values at the end of the test was less than 20% and therefore satisfied the validation criterion given in the OECD Test Guidelines.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test item attained 0% biodegradation after 28 days and therefore cannot be considered as readily biodegradable under the strict terms and conditions of OECD Guideline No. 301F.

Executive summary:

This study was performed to assess the ready biodegradability of Mannich base IPDA-PTBP in an aerobic aqueous media. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (1992) No. 301F, “Ready Biodegradability; Manometric Respirometry Test” referenced as method C.4-D of Commission Regulation (EC) No. 440/2008 and US EPA Fate, Transport, and Transformation Test Guidelines OCSPP 835.3110 (Paragraph (q)).

The test item at a concentration of 100 mg/L was exposed to sewage treatment micro-organisms with mineral medium in sealed culture vessels in diffuse light at temperatures of between 20 and 22 ºC for 28 days.

Following the recommendations of the International Standards Organisation (ISO 1995), the test item was dissolved in an auxiliary solvent prior to being adsorbed onto a filter paper and subsequent dispersal in test media. Using this method, the test item is evenly distributed throughout the test medium and the surface area of test item exposed to the test organisms is increased thereby increasing the potential for biodegradation.

The biodegradation of the test item was assessed by the measurement of daily oxygen consumption values on Days 0 to 28. Control solutions with inoculum and the reference item, aniline, together with a toxicity control were used for validation purposes.

The test item attained 0% biodegradation after 28 days and therefore cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No. 301F.

The toxicity control attained 32% biodegradation after 14 days and 33% biodegradation after 28 days thereby confirming that the test item was not toxic to the sewage treatment micro-organisms used in the test.