Buta-1,3-diene

Biodegradation in water and sediment: simulation tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: sediment simulation testing

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is readily biodegradable

Reference 2

Endpoint:

biodegradation in water: simulation testing on ultimate degradation in surface water

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Study period:

2020

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

Episuite and the BioHCWin model are well documented and commonly used QSARs for predicting the biodegradation potential of chemicals. Substances within LOA fall within the applicability domain of these models and they have been recommended by ECHA in the Information Requirement Guidelines.

Qualifier:

according to guideline

Guideline:

other: ECHA Information Requirements R.6

Principles of method if other than guideline:

BioHCwin v1.01 in EPISuite 4.1 (2013). The BioHCwin program was developed specifically for the biodegradation half-life prediction of petroleum hydrocarbons. Primary biodegradation half-lives for individual petroleum hydrocarbons are estimated using multiple linear regression against distinct molecular fragments, using a similar approach to several other biodegradation models such as those within the Biodegradation Probability Program (Biowin).

Compartment:

water

DT50:

2.8 d

Type:

not specified

Remarks on result:

other: BioHCWin prediction

Transformation products:

not measured

Conclusions:

The results of the BioHCwin predictions for 1,3-butadiene indicate that it will degrade rapidly, with an estimated half life of 2.8 days.

Executive summary:

As 1,3 -butadiene is a gas at standard temperature and pressure conducting a standard ready biodegradability test is technically difficult and based on exposure estimates the test may not be relevant. Therefore, the use of a QSAR to predict the biodegradability of 1,3 -butadiene is an appropriate technique to use a part of a weight of evidence approach. The use of BioHCwin is appropriate for 1,3-butadiene as this compound falls within the applicability domain of the model. The results indicate that 1,3 -butadiene is expected to biodegrade rapidly, with an estimated half-life of 2.8 days.

Description of key information

As 1,3 -butadiene is a gas at standard temperature and pressure conducting a standard ready biodegradability test is technically difficult and based on exposure estimates the test may not be relevant. Therefore, the use of a QSAR to predict the biodegradability of 1,3 -butadiene is an appropriate technique to use a part of a weight of evidence approach. The use of BioHCwin is appropriate for 1,3-butadiene as this compound falls within the applicability domain of the model. The results indicate that 1,3 -butadiene is expected to biodegrade rapidly, with an estimated half-life of 2.8 days.

Biodegradation in sediment tests do not need to be conducted, since 1,3-butadiene is readily biodegradable in water.

Key value for chemical safety assessment

Half-life in freshwater:

2.8 d