Paraffin waxes and Hydrocarbon waxes, oxidized

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
see read-across justifocation in section Chapter 13

Reason / purpose for cross-reference:

read-across source

Key result

Parameter:

% degradation (O2 consumption)

Value:

55

Sampling time:

28 d

Details on results:

- The toxicity control attained 45% degradation after 14 days and 55% after 28 days, confirming that the test material was not toxic to the sewage micro-organisms.
- The degradation rate calculated fro the results of DOC analysis was lower than that calculated from oxygen consumption values, which was considered to be due the sampling/analytical variation.
- Validation criteria were all met.

Results with reference substance:

- Aniline, the reference substance, attained 76% degradation after 14 days and 89% after 28 days, confirming the suitability of the test inoculum and test conditions.
- 85% degradation was calculated, after 28 days, using the DOC analysis from Days 0 and 28.

Table 1. BOD and Biodegradation Values

Sample	ThOD (mg O2/l)	Day 7		Day 14		Day 28
		BOD (mg O2/l)	Degradation (%)	BOD (mg O2/l)	Degradation (%)	BOD (mg O2/l)	Degradation (%)	Mean degradation (%)
Control R1	-	10.88	-	18.40	-	29.48	-	-
Control R2	-	10.38	-	18.66	-	31.18	-
Aniline	309	19.50	3	252.10	76	306.02	89	-
Test Material R1	265	87.96	29	139.66	46	174.98	55	55.00
Test Material R2	265	92.12	31	132.90	43	177.38	55
Toxicity Control	574	234.86	3	275.76	45	347.96	55	-

Table 2. DOC and Degradation Values

Sample	Theoretical Carbon Content (mg C/l)	Day 0			Day 28
		DOC (mg C/l)			DOC (mg C/l)
		Measured	Corrected for Control Value	% Theoretical Carbon Content	Measured	Corrected for Mean Control Values	Degradation (%)
Control R1	-	3.48	-	-	1.71	-	-
Control R2	-	-	-	-	1.54	-	-
Aniline	77.38	79.39	75.91	98.00	12.64	11.01	85
RO Water	-	1.99	-	-	-	-	-
Aniline Stock Solution	77.38	79.38	77.39	100.00	-	-	-

Validity criteria fulfilled:

yes

Interpretation of results:

other: Not readily biodegradable.

Conclusions:

Under the conditions of the test, the test material attained 55% degradation after 28 days, according to OECD 301F the test material is considered to be not readily biodegradable.

Executive summary:

In a GLP compliant study performed to the standardised guideline OECD 301F the ready biodegradability of the test material was determined by culturing predominantly domestic sewage sludge micro-organisms with the test material for 28 days. The biodegradability of the test material was determined by measuring oxygen consumption daily. Under the conditions of the test, the test material attained 55% degradation after 28 days, according to OECD 301F the test material is considered to be not readily biodegradable.

Description of key information

The ready biodegradability of the test substance was determined in a key study (Clarke, 2003) to be not readily biodegradable.

The study was performed according to GLP and the standardised guidelines OECD 301F and EPA OPPTS 835.3110.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

The key study (Clarke, 2003) is a GLP compliant study which was performed in line with standardised guidelines with a sufficient level of detail to assess the quality of the study. Predominantly domestic sewage sludge micro-organisms were exposed to the test material at 100 mg/l for 28 days under aerobic conditions. Oxygen consumption was recorded daily to quantify the observed degradation. Under the conditions of the test 55% degradation was seen, which is classed as not being readily biodegradable. The study was performed to a good standard and was assigned a reliability score of 1 using the principles for assessing data quality as set out in Klimisch (1997).