Registration Dossier

Administrative data

Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: OECD 111

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 111 (Hydrolysis as a Function of pH)
GLP compliance:
no
Remarks:
performed at a ISO lab with process similar to GLP

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
other: liquid at 22°C
Radiolabelling:
no

Study design

Analytical monitoring:
yes
Buffers:
Buffer solutions:

- Potassium Hydrogen Phthalate buffer pH 4.01: 102.1 g of KHC4H4O6 (supplied by Merck) is added to 2000mL deionised water, agitated and completed with deionised water until 10027g. The solution is effective for 2 years since the preparation. The buffer used in this report was dated from February 18, 2009.

- Phosphate buffer pH 6.86: 33.8g of KH2PO4 (supplied by Merck) and 44.3g of Na2HPO4*H2O (supplied by Merck) were added to 2000mL of deionised water, agitated and completed with deionised water until 10038g. The solution is effective for 1 year since the preparation. The buffer used in this report was dated from March 18, 2010.

- Borax buffer pH 9.18: 38.14g of NaB4O7*10H2O (supplied by Merck) was added to 2000mL of deionised water, agitated and completed with water until 10000g. The solution is effective for 2 years since the preparation. The buffer used in this report was dated from January 26, 2010.
Duration of testopen allclose all
Duration:
5 d
pH:
4
Temp.:
50
Initial conc. measured:
118.7 mg/L
Duration:
5 d
pH:
7
Temp.:
50
Initial conc. measured:
118.7 mg/L
Duration:
5 d
pH:
9
Temp.:
50
Initial conc. measured:
118.7 mg/L

Results and discussion

Preliminary study:
At the three different pH, after 5 days of incubation at 50 ± 0.5°C, less than 10% of hydrolysis was found in each case. Therefore, according to the criteria given in the guideline 111, no main study was required to conclude that the half-life time of the test substance is superior at 1 year.
Transformation products:
not measured
Total recovery of test substance (in %)open allclose all
% Recovery:
96.38 - 99.25
pH:
4
Temp.:
50 °C
Duration:
5 d
% Recovery:
92.26 - 98.94
pH:
7
Temp.:
50 °C
Duration:
5 d
% Recovery:
93.1 - 99.12
pH:
9
Temp.:
50 °C
Duration:
5 d
Dissipation DT50 of parent compoundopen allclose all
pH:
4
Temp.:
50 °C
DT50:
> 1 yr
pH:
7
Temp.:
50 °C
DT50:
> 1 yr
pH:
9
Temp.:
50 °C
DT50:
> 1 yr

Any other information on results incl. tables

8.RESULTS

8.1Preliminary test

Results of the preliminary test of perfluorohexylethyliodide at pH 4.0, 7.0 and 9.0 at 50°C were performed; the values given in the following table were measured:

Fraction Initial amount of product introduced Volume of water sample after 5 days incubation (V1) Volume of MED sample after extraction and concentration (V2) Amount in MED measured in GC (c2)
mg/L mL mL mg/L
pH 4.0 118.7 98.20 3.6 4.18
pH 7.0 118.7 98.97 3.4 4.36
pH 9.0 118.7 98.90 2.8 5.08

Concentration in water (c1) was calculated using the enrichment factor (volume of solution in dichloromethane (V2) divided by volume of aqueous sample (V1)) and the dilution factor (f). The recovery rate was between 95 and 105% and so, do not take in account. So, the formula used was: c1=c2* (V2/V1)*f

The following table resumes the results found:

Fraction Initial amount of product introduced (correspond to 100%) Dilution factor (f) Amount in water after 5 days incubation (c1) Hydrolysis percentage after 5 days incubation
mg/L mg/L %
pH 4.0 118.7 1000 117.8 0.75
pH 7.0 118.7 1000 115.2 2.95
pH 9.0 118.7 1000 110.6 6.90

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Less than 10% of hydrolysis was found after 5 days of incubation at 50°C +/- 0.5°C and for the three different pHs envisaged . According to OECD guideline 111, the test subtance can therefore be considered as hydrolytically stable with a half-life time superior than one year. No further testing is required.