4-chloroformylphthalic anhydride

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

not stated

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Remarks:

This study addressed the issue of hydrolysis from the perspective of requirements for substances that may come into contact with food via packaging material and employed distilled water as a simple food simulant. The study was performed according to an appropriate guideline, though not to GLP.

Qualifier:

equivalent or similar to guideline

Guideline:

other: Scientific Committee for Food CS/PM/1025 (August 1991)

Deviations:

no

GLP compliance:

no

Specific details on test material used for the study:

trimellitic anhydride acid chloride

Radiolabelling:

no

Analytical monitoring:

yes

Estimation method (if used):

Not relevant

Duration:

24 h

Temp.:

40 °C

Initial conc. measured:

> 5.34 - < 5.61 µg/L

Transformation products:

yes

No.:

#1

Key result

Temp.:

40 °C

DT50:

< 30 min

Remarks on result:

other: Trimellitic anhydride chloride was hydrolysed completely within 30 minutes to trimellitic acid and HCl. The hydrolysis was so fast that it was considered to be virtually instantaneous.

Table 2: Hydrolysis of the monomer in water food simulant at 40°C

Time Period (Hours)	Initial Concentration of monomer_µg/mL	Concentration of trimellitic acid produced_µg/mL	Percentage hydrolysis % w/w
0	5.61	4.99	96
0	5.34	4.72	96
0	5.34	4.84	99
½	5.61	4.98	97
1	5.61	5.05	97
3	5.34	4.60	94
4	5.34	4.80	98
24	5.34	5.01	102
24	5.34	4.84	99
24	5.34	4.88	99

Validity criteria fulfilled:

not applicable

Conclusions:

Trimellitic anhydride acid chloride was found to hydrolyse completely in water food simulant at 40 °C in less than ½ hour to trimellitic acid and hydrogen chloride gas. The hydrolysis of the monomer is so rapid that it is virtually instantaneous. Similarly rapid hydrolysis is anticipated for trimellitic anhydride and trimellitic anhydride may therefore be expected to undergo almost instantaneous conversion to trimellitic acid on contact with aqueous matrices in the environment and in vivo in exposed humans and other organisms.

Executive summary:

Trimellitic anhydride acid chloride (TMAC) was found to hydrolyse completely in water food simulant at 40 °C in less than ½ hour into trimellitic acid (TMLA) and hydrogen chloride gas. The rate of hydrolysis of the monomer is so rapid that it is virtually instantaneous.

Description of key information

According to REACH Regulation 1907/2006, Annex VIII Column 2, hydrolysis studies are not necessary for substances that are readily biodegradable. Since trimellitic anhydride mono chloride (TMAC) has been considered to be readily biodegradable (Point 5.2.1) based on a read-across approach, a study of its hydrolysis under a range of pH conditions is not required.

However, a study of the hydrolysis of trimellitic anhydride acid chloride, has been performed in the context of the requirements for substances that may come into contact with food via packaging material. This study examined the behaviour of trimellitic anhydride acid chloride in unbuffered distilled water as a simple food simulant. Trimellitic anhydride acid chloride was found to hydrolyse completely at 40 °C in less than ½ hour to trimellitic acid and hydrogen chloride gas. Hydrolysis of the monomer was virtually instantaneous.

Key value for chemical safety assessment

Half-life for hydrolysis:

0.5 h

at the temperature of:

40 °C

Additional information

Since trimellitic anhydride mono chloride has been shown to be readily biodegradable (Point 5.2.1), a study of its hydrolysis under a range of pH conditions is not strictly necessary.

However, a study of the hydrolysis of trimellitic anhydride acid chloride, has been performed in the context of the requirements for substances that may come into contact with food via packaging material. This study examined the behaviour of trimellitic anhydride acid chloride in unbuffered distilled water as a simple food simulant. Trimellitic anhydride acid chloride was found to hydrolyse completely at 40 °C in less than ½ hour to trimellitic acid and hydrogen chloride gas. Hydrolysis of the monomer was virtually instantaneous.