2-butoxyethanol

Additional information on environmental fate and behaviour

Administrative data

Endpoint:

additional information on environmental fate and behaviour

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

biotransformation and kinetics

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline available

Principles of method if other than guideline:

- Principle of test: Quantification of metabolites formed during degradation of 2-butoxyethanol
- Short description of test conditions: 3hrs exposure, then collection of metabolites by solvent extraction
- Parameters analysed / observed: Analysis of metabolites by GC-MS.

GLP compliance:

not specified

Type of medium:

aquatic

Transformation products:

yes

No.:

#1

No.:

#2

No.:

#3

As well as the transformation products, unchanged 2 -butoxyethanol was also detected.

This study was part of a larger study that examined the potential of 11 bacterial strains to degrade 2 -butoxyethanol. This particular species/strain grew the fastest and tolerated the highest substrate concentrations among the strains/species examined (and hence why it was used for this metabolite study). The maximum growth rate was 0.645 h-1 at a concentration of 5 mM (590mg/L), which was completely degraded within less than 6 h. A stable degradation of 2-BE could be achieved for concentrations of up to 30 mM (3540mg/L). Beyond that value, 2 -butoxyacetic acid

accumulated and the pH decreased to 6, inhibiting further growth.

.

Executive summary:

In a study that qualitatively measured the metabolites produced by bacterial degradation of 2 -butoxethanol, the bacterial strain Pseudomonas vancouverensis was found to produce the metabolites 2 -butoxyacetic acid, butanol and butanoic acid. These findings support the hypothesis that 2 -butoxyethanol degradation by bacteria in the environment proceeds by initial oxidation to 2 -butoxyacetic acid (as in mammals) followed by cleavage of the ether group to produce butanol and butanoic acid. The maximum growth rate was 0.645 h-1 at a concentration of 5 mM (590mg/L), which was completely degraded within less than 6 h. A stable degradation of 2-BE could be achieved for concentrations of up to 30 mM (3540mg/L).

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

- Principle of test: To identify bacterial strains that can utilise 2-butoxyethanol as a source of carbon
- Short description of test conditions: Samples used as sources of bacteria collected from a number of sources and grown in media with 2-butoxyethanol. These were then plated on solid growth medium, incubated then colonies harvested and DNA sequenced using PCR technique.
- Parameters analysed / observed: strains that had grown under the prescribed conditions using gene sequencing.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

2-butoxyethanol

EC Number:

203-905-0

EC Name:

2-butoxyethanol

Cas Number:

111-76-2

Molecular formula:

C6H14O2

IUPAC Name:

2-butoxyethanol

Results and discussion

Any other information on results incl. tables

The following strains were isolated and all found capable of utilising 2 -butoxyethanol as a carbon source:

Bacteria	Gram	Source (all in Germany)
Pseudomonas knackmussii	Gram-negative	Forest soil, Stuttgart
Pseudomonas putida	Gram-negative	Forest soil, Stuttgart
Hydrogenophaga pseudoflava	Gram-negative	Forest soil, Stuttgart
Pseudomonas umsongensis	Gram-negative	Forest soil, Stuttgart
Gordonia terrae	Gram-positive	Biotrickling filter, Stuttgart
Pseudomonas extremaustralis	Gram-negative	Biotrickling filter, Stuttgart
Pseudomonas plecoglossicida	Gram-negative	Activated sludge, Stuttgart
Pseudomonassp	Gram-negative	Activated sludge, Stuttgart
Pseudomonas putida	Gram-negative	Bioscrubber, Rastatt
Pseudomonas vancouverensis	Gram-negative	Bioscrubber, Rastatt
Cupriavidus oxalaticus	Gram-negative	Activated sludge, Stuttgart

Applicant's summary and conclusion

Executive summary:

In a study to examine how widely distributed are bacteria capable of utilising 2 -butoxyethanol as a source of carbon, all 11 bacterial strains sourced from four different bacterial colonies (two biofilter/bioscrubbers that can be considered adapted sources) and forest soil and activated sludge that can be considered non-adapted) were found capable of degrading the substance. It can be concluded that the bacteria capable of degrading 2 -butoxyethanol are widespread.