Benzophenone-3,3':4,4'-tetracarboxylic dianhydride

Endpoint summary

Description of key information

BTDA is hydrolysed in contact with water, and likely is poorly absorbed and metabolised.  Distribution to organs is not significant and excretion is likely through the fecal route.  It has a low potential for bioaccumulation.
Absorption: Low water solubility, low order of acute oral toxicity and lack of systemic toxicity suggest relatively low potential for absorption across the skin, gastrointestinal tract and respiratory tract.  BTDA shows no significant dermal or ocular absorption.  The weight of evidence suggests that BTDA may be absorbed in the respiratory tract, depending upon the size particle.
Distribution: Based on the lack of systemic toxicity and the presence of slight irritation in the gastrointestinal and respiratory tract, distribution following oral or inhalation exposure is limited to the primary organ of contact.  Given the lack of systemic toxicity it is unlikely that significant quantities of BTDA are distributed to or expressed in breast milk.
Metabolism: In vitro genetic toxicity studies do not suggest that BTDA is metabolised to reactive species. BTDA hydrolysis products may cause slight irritation following direct contact with the moist environment of GI tract, eyes and respiratory tract.
Excretion: Fecal excretion is likely the major route of elimination of unabsorbed and unchanged BTDA.

Key value for chemical safety assessment

Bioaccumulation potential:

low bioaccumulation potential

Absorption rate - oral (%):

10

Absorption rate - dermal (%):

10

Absorption rate - inhalation (%):

10

Additional information

1,3-Isobenzofurandione, 5,5'-carbonylbis- (BTDA) is a solid low molecular weight anhydride, susceptible to hydrolysis in water. BTDA is not acutely toxic by the oral, dermal or inhalation routes in animal studies. Low water solubility and lack of systemic toxicity would suggest relatively low potential for absorption across the skin, gastrointestinal tract and respiratory tract. Particulates may be absorbed in the lung and have increased potential to cause local toxicity. Distribution to organs is not significant and there is no evidence that BTDA is metabolized. Excretion of unchanged BTDA is likely via fecal elimination however the database is limited. Future opportunities to undertake selected in vivo studies on BTDA will provide additional knowledge, useful for risk assessment, on the toxicokinetic behavior of this substance.