β-methyl-3-(1-methylethyl)benzenepropanal

Hydrolysis

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Experimental results from this study may be disturbed by the easy oxidisability of the test substance. For the same reason, the environmental relevance of the present test results in aerobic conditions is of minor importance compared to the degradation by air oxidisation (direct or dissolved) which is much faster.

Justification for type of information:

FLORHYDRAL has been demonstrated to be READILY BIODEGRADABLE (74% biodegradation after 28 days, ful-filling the 10-Day window crietria) under the strict testing conditions of the OECD 301F test guideline, as such, this study can be waived.

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): Florhydral
- Analytical purity: 97.6% (GC)
- Lot/batch No.: 213739

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

Preliminary Test - Peformed at 50 °C :
- pH4 - Samples taken for analysis at 0, 3, 25, 50 and 73 hours;
- pH7 - Samples taken for analysis at 0, 3, 25, 50 and 72 hours;
- pH9 - Samples taken for analysis at 0, 3, 25, 50 and 72 hours

Test at 25°C :
- pH4, pH7, pH9 - Samples taken at 22, 89, 111, 136, 159, 183, 255, 202, 351, 499, 519 hours

Buffers:

pH4.00 +/- 0.02 at 20°C :
Citric Acid 0.056 mole/L
NaOH 0.11 mole/L
HCl 0.044 mole/L

pH7.00 +/- 0.02 at 20°C :
KH2PO4 0.026 mole/L
Na2HPO4 0.041 mole/L

pH9.00 +/- 0.02 at 20°C :
H3BO3 0.05 mole/L
KCl 0.05 mole/L
NaOH 0.022 mole/L

Estimation method (if used):

HPLC-UV/VIS Detection

Details on test conditions:

Glassware :
All glassware was thoroughly cleaned and sterilised in an oven (160°C, overnight) prior to use.

Hydrolysis experiments were performed in amber-glass bottles (volume 250 mL) with ground-glass 4 mm (I.D.) passage stopcocks allowing sampling with a syringe needle through the stopcock with a minimum intake of air.

A constant temperature water bath with a immersed six-position magnetic stirrer, was used to maintain to +/- 0.1°C temperature.

Duration:

0 h

pH:

3.9

Temp.:

50 °C

Initial conc. measured:

292 other: Peak area

Remarks:

In the initial screening test, samples of pH4 incubates were taken at 0, 3, 25, 50 and 73 hours.

Duration:

73 h

pH:

3.9

Temp.:

50 °C

Initial conc. measured:

209 other: Peak Area

Remarks:

In the initial screening test, samples of pH4 incubates were taken at 0, 3, 25, 50 and 73 hours.

Duration:

0 h

pH:

7.2

Temp.:

50 °C

Initial conc. measured:

252 other: Peak Area

Remarks:

In the initial screening test, samples of pH7 incubates were taken at 0, 3, 25, 50 and 72 hours.

Duration:

72 h

pH:

7.2

Temp.:

50 °C

Initial conc. measured:

227 other: Peak Area

Remarks:

In the initial screening test, samples of pH7 incubates were taken at 0, 3, 25, 50 and 72 hours.

Duration:

0 h

pH:

8.8

Temp.:

50 °C

Initial conc. measured:

213 other: Peak Area

Remarks:

In the initial screening test, samples of pH9 incubates were taken at 0, 3, 25, 50 and 72 hours.

Duration:

72 h

pH:

8.8

Temp.:

50 °C

Initial conc. measured:

171 other: Peak Area

Remarks:

In the initial screening test, samples of pH9 incubates were taken at 0, 3, 25, 50 and 72 hours.

Duration:

22 h

pH:

4

Temp.:

25 °C

Initial conc. measured:

115 other: Peak Area

Remarks:

Results of test at 25°C : pH4 Replicate A - Samples taken at 22, 89, 111, 136, 159, 183, 255, 303, 351, 499 and 519 hours.

Duration:

519 h

pH:

4

Temp.:

25 °C

Initial conc. measured:

61 other: Peak Area

Remarks:

Results of test at 25°C : pH4 Replicate A - Samples taken at 22, 89, 111, 136, 159, 183, 255, 303, 351, 499 and 519 hours.

Duration:

22 h

pH:

4

Temp.:

25 °C

Initial conc. measured:

99 other: Peak Area

Remarks:

Results of test at 25°C : pH4 Replicate B- Samples taken at 22, 89, 111, 136, 159, 183, 255, 303, 351, 499 and 519 hours.

Duration:

519 h

pH:

4

Temp.:

25 °C

Initial conc. measured:

55 other: Peak Area

Remarks:

Results of test at 25°C : pH4 Replicate B- Samples taken at 22, 89, 111, 136, 159, 183, 255, 303, 351, 499 and 519 hours.

Duration:

22 h

pH:

7

Temp.:

25 °C

Initial conc. measured:

125 other: Peak Area

Remarks:

Results of test at 25°C : pH7 - Samples taken at 22, 89, 111, 136, 159, 183, 255, 303, 351, 499 and 519 hours.

Duration:

519 h

pH:

7

Temp.:

25 °C

Initial conc. measured:

66 other: Peak Area

Remarks:

Results of test at 25°C : pH7 - Samples taken at 22, 89, 111, 136, 159, 183, 255, 303, 351, 499 and 519 hours.

Duration:

22 h

pH:

9

Temp.:

25 °C

Initial conc. measured:

105 other: Peak Area

Remarks:

Results of test at 25°C : pH9 - Samples taken at 22, 89, 111, 136, 159, 183, 255, 303, 351, 499 and 519 hours.

Duration:

519 h

pH:

9

Temp.:

25 °C

Initial conc. measured:

86 other: Peak Area

Remarks:

Results of test at 25°C : pH9 - Samples taken at 22, 89, 111, 136, 159, 183, 255, 303, 351, 499 and 519 hours.

Number of replicates:

One replicate for each pH in the initial screening test.

Two replicates for pH4 samples in the definitive study, and one replicate for both pH7 and pH9.

Positive controls:

no

Negative controls:

no

Preliminary study:

Initial screening study performed at 50°C :
pH4 - Following 73 hours of incubation 28% loss of the test item was observed;
pH7 - Following 72 hours of incubation 11% loss of the test item was observed;
pH9 - Following 72 hours of incubation 20% loss of test item was observed.

Transformation products:

not measured

Details on hydrolysis and appearance of transformation product(s):

Definitive Study Performed at 25°C :
FLORHYDRAL is slowly transformed in aqueous solutions at pH4, 7 and 9 at 25°C.
The kinetics are roughly pseudo-first order and calculated half-life times at 25°C are :
pH4 = 710 hours
pH7 = 620 hours
pH9 = 2000 hours
Experimental results may be disturbed by the easy oxidisability of the test substance, where the impossibility to totally exclude air from the test system could render the aldehyde function of FLORHYDRAL sensitive to oxidation in to the corresponding carboxylic acid form. Previous experiments have demonstrated that oxidation by dissolved oxygen occurs in hours (i.e. much more rapidly than hydrolysis).
The environmental relevance of the present test results is of minor importance compared to transformation via air oxidation (direct or dissolved) which is much more rapid.

pH:

4

Temp.:

25 °C

Hydrolysis rate constant:

0.001 h-1

DT50:

710 h

St. dev.:

82

Type:

(pseudo-)first order (= half-life)

Key result

pH:

7

Temp.:

25 °C

Hydrolysis rate constant:

0.001 h-1

DT50:

620 h

St. dev.:

39

Type:

(pseudo-)first order (= half-life)

pH:

9

Temp.:

25 °C

Hydrolysis rate constant:

0 h-1

DT50:

2 000 h

St. dev.:

355

Type:

(pseudo-)first order (= half-life)

Validity criteria fulfilled:

not specified

Conclusions:

Hydrolytic Half-Life of FLORHYDRAL at 25 °C :
pH4 = 710 hours (29.6 Days)
pH7 = 620 hours (25.8 Days)
pH9 = 2000 hours (83.3 Days)
Experimental results may be disturbed by the easy oxidisability of the test substance, where the impossibility to totally exclude air from the test system could render the aldehyde function of FLORYHDRAL sensitive to oxidation in to the corresponding carboxylic acid form. Previous experiments have demonstrated that oxidation by dissolved oxygen occurs in hours (i.e. much more rapidly than hydrolysis).
The environmental relevance of the present test results is of minor importance compared to transformation via air oxidation (direct or dissolved) which is much more rapid.

Reference 2

Endpoint:

hydrolysis

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is readily biodegradable

Justification for type of information:

FLORHYDRAL has been demonstrated to be READILY BIODEGRADABLE (74% biodegradation after 28 days, fulfilling the 10-Day window crietria) under the strict testing conditions of the OECD 301F test guideline, as such, hydrolysis of FLORHYDRAL can be waived.

Conclusions:

FLORHYDRAL has been demonstrated to be READILY BIODEGRADABLE (74% biodegradation after 28 days, fulfilling the 10-Day window crietria) under the strict testing conditions of the OECD 301F test guideline, as such, hydrolysis of FLORHYDRAl can be waived.

Description of key information

FLORHYDRAL has been demonstrated to be READILY BIODEGRADABLE (74% biodegradation after 28 days, fulfilling the 10-Day window crietria) under the strict testing conditions of the OECD 301F test guideline, as such, hydrolysis of FLORHYDRAl can be waived.

A hydrolysis study has, nonetheless, been performed.  Hydrolytic Half-Life of FLORHYDRAL at 25 °C :

pH4 = 710 hours (29.6 Days)

pH7 = 620 hours (25.8 Days)

pH9 = 2000 hours (83.3 Days)

Experimental results may be disturbed by the easy oxidisability of the test substance, where the impossibility to totally exclude air from the test system could render the aldehyde function of FLORHYDRAL sensitive to oxidation in to the corresponding carboxylic acid form. Previous experiments have demonstrated that oxidation by dissolved oxygen occurs in hours (i.e. much more rapidly than hydrolysis).

The environmental relevance of the present test results is of minor importance compared to transformation via air oxidation (direct or dissolved) which is much more rapid.

Key value for chemical safety assessment

Half-life for hydrolysis:

25.8 d

at the temperature of:

25 °C

Additional information

FLORHYDRAL has been demonstrated to be READILY BIODEGRADABLE (74% biodegradation after 28 days, fulfilling the 10-Day window crietria) under the strict testing conditions of the OECD 301F test guideline, as such, hydrolysis of FLORHYDRAl can be waived.

A hydrolysis study has, nonetheless, been performed

Hydrolytic Half-Life of FLORHYDRAL at 25 °C :

pH4 = 710 hours (29.6 Days)

pH7 = 620 hours (25.8 Days)

pH9 = 2000 hours (83.3 Days)

Experimental results may be disturbed by the easy oxidisability of the test substance, where the impossibility to totally exclude air from the test system could render the aldehyde function of FLORHYDRAL sensitive to oxidation in to the corresponding carboxylic acid form. Previous experiments have demonstrated that oxidation by dissolved oxygen occurs in hours (i.e. much more rapidly than hydrolysis).

The environmental relevance of the present test results is of minor importance compared to transformation via air oxidation (direct or dissolved) which is much more rapid.