EXPERT STATEMENT 

Study Title: 

HVDROL YSIS DETERMINATION OF 

DEA/Acid anhydride reaction product AT DIFFERENT pH VALUES 

Data Requirement I Test Guidelines: 

OECD No. 111 

EEC Directive 92/69, C. 7 

Study Director: 

Mrs. Alessandra Tognucci 

Study Completion Date: 

February 05, 2004 

Test Facility: 

RCC Ltd 

Environmental Chemistry & Pharmanalytics 

CH-4452 ltingen/Switzerland 

Sponsor: 

Rockwoollnternational A/S 

Hovedgaden 584 

DK-2640 Hedehusene 

Denmark 

RCC Study Number: 

848638 

Page 1 of 9 
RCC Study Number 848638 

DEN Acid anhydride reaction product 

Title: 

Sponsor: 

Monitoring Scientist: 

Expert Statement by: 

STATEMENT 

EXPERT STATEMENT 

Hydrolysis Determination of DEAl Acid anhydride 

reaction product at Different pH Values 

Rockwool International A/S 

Hovedgaden 584 

DK-2640 Hedehusene 

Denmark 

Mr. Flemming A. Simonsen 

Danish Toxicology Centre 

Kogle Aile 2 

DK-2970 H0RSHOLM 

Denmark 

Mrs. Alessandra Tognucci 

RCC Ltd 

Environmental Chemistry & Pharmanalytics 

CH-4452 ltingen/Switzerland 

Page2 

Under Study 848638, RCC was supposed to determine the hydrolysis of DEA/Acid anhydride 

reaction product at different pH values according to OECD Guideline No. 111 and EEC 

Directive 92/69, C.?, respectively. 

DEAl Acid anhydride reaction product is a complex mixture of different monomers, dimers, 

trimers and polymers. According to the guidelines, the hydrolysis test is only applicable to 

pure compounds. The hydrolysis determination of a complex mixture is not possible during 

one single test. If the hydrolysis behaviour of DEAl Acid anhydride reaction product ought to 

be determined, this must be performed with each of the respective pure substance in a 

separate test. 

Furthermore, it is expected that it will not be possible to follow properly the disappearance of 

some ingredients if the hydrolysis would be determined in the mixture. Dimers may hydrolyse 

to monomers and trimers may hydrolyse to dimers and monomers. During polymer 

hydrolysis, dimers or trimers could be formed as intermediates from polymer hydrolysis 

which would make it difficult to determine a reasonable hydrolysis kinetics for .these 

intermediates. It is also beyond the scope of the guidelines to investigate complex hydrolysis 

kinetics. 

Additionally, this mixture cannot be analysed with one single chromatographic technique. 

Several techniques like size exclusion chromatography, ion chromatography, derivatization 

followed by HPLC analysis and conventional reversed phase HPLC were used for the 

analysis of the mixture. Different detectors had to be used for the detection of the 

components: refractive index detector, conductivity detector and UV detector. 

It is considered that the analytical methods are not suitable to follow a hydrolysis of the 

mixture with exception of the monomers. 

RCC Study Number 848638 

DEA/Acid anhydride reaction product 

EXPERT STATEMENT Page 8 

For the hydrolysis of the mixed ester/amide trimers, only ester hydrolysis was relevant for the 

rate determining step. Amides were estimated to be stable with half-lives> 1 year. 

Ester hydrolysis at pH 8 is estimated to proceed slower by a factor of 1 0 compared to pH 9. 

It is expected that polymers will be only susceptible to ester hydrolysis at pH 8 and 9. 

However, some ester functional groups may be shielded or sterically hindered that they are 

much less suscessible for hydrolysis. 

Conclusion 

The test item mixture DEAl Acid anhydride reaction product was not suitable to perform a 

hydrolysis test according to the OECD guideline 111 and EEC Directive 92/69, C.7, 

respectively. The method was not applicable to a complex mixture of different compounds. 

QSAR based estimates for the acid- and base-catalysed hydrolysis rate led to the conclusion 

that DEA/Acid anhydride reaction product will not hydrolyse in an slightly acidic to neutral 

aquatic environment (pH 4 to pH 7). Under these conditions both ester and amide type 

functional groups of dimers, trimers and polymers of DEAl Acid anhydride reaction product 

were estimated to be hydrolytically stable. 

Under alkaline conditions of pH 8 to 9, only ester type functional groups of trimellitic acid with · 

diethanolamine are expected to be hydrolysed. Amides and esters of tetrahydrophtalic acid 

were estimated to be stable at these pHs. Hydrolysis of mixed ester/amide trimers will lead 

to stable amide linked dimers, diethanolamine and trimellitic acid as products. Ester linked 

dimers and trimers of trimellitic acid with diethanolamine are expected to hydrolyse to the 

corresponding monomers with estimated half-lives of about 0.5 to 3 days at pH 9 and about 

5 to 30 days at pH 8. 

References 

[1] 

[2] 

W.J. Lyman, W.F. Reehl, D.H. Rosenblatt: Handbook of Chemical Property 

Estimation Methods, American Chemical Society, 1990. 

Estimation Program Interface (EPI) Suite Version 3.11, U.S. Environmental Protection 

Agency, HYDROWINTM, June 10,2003. 
RCC Study Number 848638 EXPERT STATEMENT 

DEAl Acid anhydride reaction product 

RCC Environmental Chemistry & Pharmanalytics 

Mrs. Alessandra Tognucci 

Study Director 

Dr. Jorn SchreitmOIIer 

Manager of Analytical Chemistry 

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Page9