Magnesium dipropan-2-olate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study without detailed documentation.

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method C.5 (Degradation: Biochemical Oxygen Demand)

Deviations:

yes

Remarks:

0.5 mg/l allylthiourea in each test to prevent nitrification

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method C.6 (Degradation: Chemical Oxygen Demand)

Deviations:

not specified

Remarks:

no details were provided

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, domestic (adaptation not specified)

Details on inoculum:

The BOD tests were conducted with partly adapted effluent from a biological sanitary waste treatment plant.

The 500 ml test solutions were seeded with a filtered 10 ml volume of the effluent from a biological sanitary waste treatment plant. In some cases an adapted seed was prepared and used.

Duration of test (contact time):

5 d

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance:

other: mixture of glucose and glutamic acid

Key result

Parameter:

% degradation (O2 consumption)

Value:

53

Sampling time:

5 d

Parameter:

BOD5

Value:

1.19 other: g O2/g test mat. (non-adapted)

Parameter:

BOD5

Value:

1.72 other: g O2/g test mat. (adapted)

Parameter:

COD

Value:

2.23 g O2/g test mat.

Parameter:

BOD5*100/COD

Value:

53 other: % (non-adapted BOD)

Parameter:

BOD5*100/COD

Value:

77 other: % (adapted BOD)

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

A BOD5/COD ratio ≥ 0.5 is considered as indicative of rapid degradation. Thus, a substance which passes this screening test is considered likely to biodegrade 'rapidly' in the aquatic environment, and is thus unlikely to be persistent.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Data waiving:

study technically not feasible

Justification for data waiving:

the study does not need to be conducted because the substance is inorganic

Description of key information

Magnesium isopropanolate hydrolyses within minutes in contact with moisture or water into isopropanol and magnesium hydroxide.

Both hydrolysis products are natural occuring substances.

The hydrolysis product isopropanol has a BOD5/ThOD ratio of 0.50, and is therefore considered to be readily degradable. The result is supported from literature, e.g. peer reviewed and published in the HSDB data base (https://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+116) cited as follows:

Isopropanol was readily degraded in a variety of microbial degradation tests. Utilizing the Japanese MITI test, 86% of the Theoretical BOD was

reached in 2 weeks indicating that biodegradation is an important environmental fate process.

Acetone has been identified as a metabolite in anaerobic degradation in sludge.

The hydrolysis product magnesium hydroxide is an inorganic substance and a biodegradation test is not applicable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable