1,2,3-Propanetricarboxylic acid, 2-hydroxy-, chromium(3+) salt (1:1)

Endpoint summary

Description of key information

Animal experiments show that trivalent chromium salts can cause sensitisation when injected intradermally. The potency of trivalent chromium as a sensitiser is lower than hexavalent chromium. The potential for sensitisation appears to relate to solublity in water and therefore, it is considered that the chromium citrate is very likely positive.

Not further testing is considered necessary.

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Thirteen guinea-pigs were given chromium chloride hexahydrate by three subcutaneous injections in the nape 1 week apart. The sensitizing injections contained 0.5 ml of FCA with 0.5 ml of 3.4 × 10−2 mol chromium chloride hexahydrate/l. Three weeks later, the animals were tested with an intradermal injection into clipped or epilated skin. The eliciting dose was 0.1 ml of 4.2 × 10−4 mol chromium chloride hexahydrate/l.

After 48 h, this produced moderate positive responses in 10 of the 13 animals, whereas the control animals (injected only with FCA) showed no reactions. In the same study, sensitization to hexavalent chromium was achieved by intradermal injections of potassium dichromate with 10-fold lower concentrations than required for sensitization to chromium chloride. Of 26 guinea-pigs sensitized to potassium dichromate, all reacted to intradermally applied chromium chloride.

Of the 10 guinea-pigs sensitized to chromium chloride, 3 elicited weaker cross-reactions after intradermal injection of chromium nitrate (9.6 × 10-4 mol/l) and sulfate (2.4 × 10−4 mol/l).

Using the same study method, the authors also attempted to sensitize guinea-pigs with chromium acetate and chromium oxalate, but without success