Octyl methacrylate

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

no GLP

Justification for type of information:

Read across from the 2 Ethylhexyl methacrylate category member donor substance.
REPORTING FORMAT FOR THE CATEGORY APPROACH
see attached category document
PM_Lower Alkyl (C1-C8) Methacrylates
This is a category (C1-C8 Lower Alkyl Methacrylates) with clear trends in the physicochemical properties of its members, related to molecular weight, molecular size and hydrophilicity.
The substances of the category C1-C8 Lower Alkyl Methacrylates are all readily biodegradable. This was demonstrated in several guideline studies which cover the range of C1 to C8. Please see Chapter 4.1.2.1.1 Results on screening tests for biodegradation in water).

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

GLP compliance:

no

Analytical monitoring:

not specified

Details on test conditions:

-Preliminary Test  
a) Water Temperature: 50 ºC  
b) Nominal Concentration: ca. 0.5 mg/L  
c) pH: pH 4 and 7  
d) Number of Replicates: 2  
e) Test Period: 5 days  
f) Exposure Vessel Type: Glass Vial

-Final Test  
a) Water Temperature: pH9; 60, 70, 80 ºC  
b) Nominal Concentration: ca. 0.5 mg/L  
c) pH: pH 9  
d) Number of Replicates: 2

Number of replicates:

preliminary test =2 replicates

Transformation products:

not specified

pH:

4

Temp.:

50 °C

Remarks on result:

other: stable

pH:

7

Temp.:

50 °C

Remarks on result:

other: stable

pH:

9

Temp.:

25 °C

DT50:

58.7 d

-Test substance was stable at pH 4 and pH 7, both at 50 ºC in preliminary test.
-The half life and the rate constant of this chemical at pH 9 were 58.7 days and 4.92 E-4/hour, at 25 ºC in water,respectively.

Conclusions:

Using a valid modeling method, the test substance was stable at pH 4 and pH 7, both at 50 ºC. The half life and the rate constant of this chemical at pH 9 were 58.7 days and 4.92 E-4/hour, at 25 ºC in water, respectively.

Executive summary:

Using a valid modeling method, the test substance was stable at pH 4 and pH 7, both at 50 ºC. The half life and the rate constant of this chemical at pH 9 were 58.7 days and 4.92 E-4/hour, at 25 ºC in water, respectively.

Description of key information

Read across to category member 2-ethylhexyl methacrylate:

stable at pH 4 and pH 7, hydrolyses slowly at pH 9

Additional information

Read across to category member 2-ethylhexyl methacrylate:

Abiotic degradation by hydrolysis of 2-ethylhexyl methacrylate was measured in an OECD guideline study. 2-EHMA was stable at pH 4 and pH7. At pH9 the measured half-life (t 1/2 ) for 2-EHMA at 25 °C is 58 days. Since 2-EHMA is readily biodegradable, hydrolysis appears not to be an important aqueous degradation process for this chemical.