Propane-1,2,3-triyl 2-ethylhexanoate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 Nov - 14 Dec 2001

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study with acceptable restrictions: Inoculum is not specified.

Qualifier:

according to guideline

Guideline:

other: Circular on Test Methods of New Chemical Substances (Japan), ready biodegradability test

Deviations:

no

GLP compliance:

yes

Remarks:

other: according to the Japanese GLP Standard

Oxygen conditions:

aerobic

Inoculum or test system:

not specified

Details on inoculum:

- Source of inoculum/activated sludge: purchased at Chemicals Evaluation and Research Institute, Japan

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: medium as recommended in guideline
- Test temperature: 25 ± 1 °C

TEST SYSTEM
- Culturing apparatus: closed oxygen consumption measuring machine with 300 mL culture bottle
- Number of culture flasks/concentration: 3 (sludge + test sub.)

SAMPLING
- Sampling frequency: continuously
- Sterility check if applicable: no

CONTROL AND BLANK SYSTEM
- Inoculum blank: 1
- Abiotic sterile control: 1 (water + test sub.)

Reference substance:

aniline

Parameter:

% degradation (O2 consumption)

Value:

85

Sampling time:

28 d

Details on results:

A biodegradation of 85% was reached within a time period of 28 days. No 10-day window is required for this test. Hence, the substance is readily biodegradable according to OECD criteria.

Results with reference substance:

The oxygen consumption for aniline in the above used test system reached 57% and more than 60% degradation after 7 days and 14 days, respectively.

Table 1: Results of analysis of BOD, DOC and HPL

		water + test sub.	Treatment (sludge + test sub.)			Theoretical Amount	Mean (sample 1 – 3)
			replicate 1	replicate 2	replicate 3
BOD*	[mg]	0.0	63.7	62.1	64.0	74.4
	[% ]	-	86	83	86		85
DOC	[mg/L]	4.0	1.0	1.4	1.8	68.9
HPLC**	[mg/L]	65.4	1.7	3.2	1.7	100
	[% ]***	35	98	97	98		98

*: Treatments were calculated by subtracting blank values.

**: Residue of test substance

***: Disappearance rate was calculated as followed: Residue percentage = (Theoretical amount - Residue amount) / Theoretical amount x 100. Residue percent of DOC was not calculated due to the low water solubility.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Description of key information

Readily biodegradable: 85% (O2 consumption) in 28 days 

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

One study investigating the ready biodegradability of Propane-1,2,3-triyl 2-ethylhexanoate (CAS No. 7360-38-5) is available. The study was conducted by a Japanese authority according to the Japanese guideline “Circular on Test Methods of New Chemical Substances, ready biodegradability test” under aerobic conditions (METI, 2002). The inoculum was not specified. Based on O2 consumption a mean degradation of 85% was observed after 28 days. No 10-day window is required. Hence, the test substance is determined to be readily biodegradable according to OECD criteria.