2-Propenoic acid, 2-fluoro-, methyl ester

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1/4/15 to 2/7/15

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: A recent study, conducted according to an OECD guideline and GLP standards.

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Qualifier:

according to guideline

Guideline:

EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)

GLP compliance:

yes

Radiolabelling:

no

Analytical monitoring:

no

Duration:

24 h

Initial conc. measured:

1 g/L

Preliminary study:

At pH 4 less than 10% hydrolysis after 5 days at 50 °C, equivalent to a half-life of greater than 1 year at 25 °C.
At pH 7, the extent of hydrolysis after 4 hours indicated that a further test (Tier 2) was required to estimate the rate constant and half-life at 25 °C.
At pH 9, the extent of hydrolysis after 4 hours indicated that a further test (Tier 2) was required to estimate the rate constant and half-life at 25 °C.

Transformation products:

not measured

pH:

7

Temp.:

50 °C

Hydrolysis rate constant:

0.096 h-1

DT50:

7.23 h

pH:

7

Temp.:

60 °C

Hydrolysis rate constant:

0.195 h-1

DT50:

3.55 h

pH:

7

Temp.:

70 °C

Hydrolysis rate constant:

0.454 h-1

DT50:

1.53 h

pH:

9

Temp.:

30 °C

Hydrolysis rate constant:

0.385 h-1

DT50:

1.8 h

pH:

9

Temp.:

40 °C

Hydrolysis rate constant:

0.861 h-1

DT50:

0.805 h

pH:

9

Temp.:

50 °C

Hydrolysis rate constant:

2.66 h-1

DT50:

0.261 h

Validity criteria fulfilled:

yes

Conclusions:

Assessment of hydrolytic stability was carried out using a standardised protocol equivalent to the OECD Test Guideline 111.
At pH 4 less than 10% hydrolysis after 5 days at 50 °C, equivalent to a half-life of greater than 1 year at 25 °C.
At pH 7, the extent of hydrolysis after 4 hours indicated that a further test (Tier 2) was required to estimate the rate constant and half-life at 25 °C.
At pH 9, the extent of hydrolysis after 4 hours indicated that a further test (Tier 2) was required to estimate the rate constant and half-life at 25 °C.

Executive summary:

Assessment of hydrolytic stability was carried out using a procedure designed to be compatible with Method C7 Abiotic Degradation, Hydrolysis as a Function of pH of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 111 of the OECD Guidelines for Testing of Chemicals, 13 April 2004. The results are as follows:

pH	Rate constant (hr^-1)	Estimated half-life at 25 °C
4	-	> 1 year
7	9.98 x 10^-3	69.4 hours
9	0.215	3.23 hours

Description of key information

A reliable study (Klimisch 1) is available to assess the hydrolytic stabilty of 2 -propenoic acid, 2 -fluoro, methyl ester at the environmentally relevant pHs of 4, 7 and 9. The study was conducted to GLP and followed internationally accepted guidelines.

At pH 4 less than 10% hydrolysis after 5 days at 50 °C, equivalent to a half-life of greater than 1 year at 25°C.

At pH 7 the half-life was estimated to 69.4 hours at 25°C.

At pH 9 the half-life was estimated to be 3.2 hours at 25°C

Key value for chemical safety assessment

Half-life for hydrolysis:

3.2 h

at the temperature of:

25 °C

Additional information

A preliminary assessment of the hydrolytic stability of 2-propenoic acid, 2-fluoro, methyl ester was completed at the environmentally relevant pHs of 4, 7 and 9. The results obtained indicated at pH 4 less than 10% hydrolysis was measured after 5 days at 50°C, equivalent to a half-life of greater than 1 year and no further testing is required. At pHs 7 and 9 the extent of hydrolysis after 4 hours indicated that 2-propenoic acid, 2-fluoro, methyl ester is hydrolytically unstable and half-lives of 69.4 and 3.2 hours at 25°C for pH 7 and 9, respectively, were estimated.