Registration Dossier

Diss Factsheets

Environmental fate & pathways

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

Constituent 1
Chemical structure
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.

Categories Display