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Description of key information

No studies on the skin or eye irritation of triammonium hydrogen ethylenediaminetetraacetate are available. However several studies using EDTA free acid, Na or diammonium salts of EDTA are available.  (For read-across justification also refer to section 13).
Diammonium dihydrogen ethylenediaminetetraacetate is not irritating to the skin (DOW, 1982).
As the irritating effect is influenced by the pH it is reasonable to assume that the eye irritating effect of (NH4)3 EDTA(pH 7 - 8) is less than the eye irritating effect of the alkaline Na4EDTA salt (pH =11). Therefore, a read-across to Na2H2EDTA with a similar pH value (pH 4-5) was employed.

Key value for chemical safety assessment

Additional information

Skin irritation:

In a skin irritation study (DOW, 1982) six male New Zealand White albino rabbits weighing between 1.6 and 2.1 kg on receipt were used. Animals were acclimatized were for a two week period and were maintained on Big Red Rabbit Chow and city water ad libitum.

The animals were prepared by clipping their sides with an electric clipper 24 hours before the experiment. Two experimental areas, each measuring 25×25 mm, were prepared on each animal; one site was left intact, the other one was baraded by means of shallow incisions through the stratum corneum without causing bleeding. An amount of 500 mg of the undiluted test material were applied to each test site by means of a double layer of surgical gauze which was then covered by over wrapping with pure latex rubber dental dam and the site was immobilized by means of adhesive bandages. All bandages, sheeting, gauze, etc. were removed 24 hours after application. All skin changes, if any, were observed, scored and recorded according to the prescribed procedure at this time, and again at 72 hours after the time of application. The animals were then observed for an additional week. The only observable effect was gradual healing of residual skin changes, if any.

 No systemic effects were observed in any of the animals, either during the experimental period or afterwards.

 The primary dermal irritation score was 1.75. So the test material is classified as not irritating to skin according to EU criteria.

In a skin irritation study performed by BASF (1973) two rabbits were exposed occlusively for 1, 5 or 15 minutes on the back to a 50% aqueous solution of edetic acid. Two additional rabbits were exposed to the same solution for 20 h on the back and at the ear. The skin of the animals was observed for 8 days. No skin irritation was observed on the back of the animals at any exposure period tested. Solely a slight erythema could be observed on the ear of the animals which was fully reversible within 48 h.

Another skin irritation study which was performed according to OECD guideline 404 the skins of 2 male and 1 female rabbits were exposed to 0.5 g of an 80% aqueous preparation of Trilon B Powder (edetic acid tetrasodium salt, 80% aqueous preparation) for an occlusive exposure period of 4 hours. For erythema medium scores after 24/48/72 hours of 1/0/0.3 were documented, redness had resolved after 8 days. No edema was noted (BASF, 1982).

In a skin irritation study performed by BASF (1973) two rabbits were exposed occlusively for 1, 5 or 15 minutes on the back to a 50% aqueous solution of Na2EDTA. Two additional rabbits were exposed to the same solution for 20 h on the back and at the ear. The skin of the animals was observed for 7 days. Both animals developed a mild erythema 24 h after application (grad 1 or grade 2 respectively) which was fully reversible within 48 or 72 h. No edema was observed. A well defined erythema was observed on the ear of both animals, which was fully reversible within 48 h.

Eye irritation:

In an irritation study (BASF, 1973) with Na2EDTAWhite Vienna rabbits were used. Approximately 50 mg of the test substance were applied to the conjunctival sac of one eye of 2 animals.The other eye served as control and was treated with 50 mg talcum powder

The test substance was not washed out and the animals were observed for 8 days.A slight redness of the eye (scale 1) was observed in both animals, which was fully reversible within 8 days.

Justification for classification or non-classification

Based on the results obtained in the toxicity studies and taking into account the provisions laid down in Council Directive 67/548/EEC and CLP, a classification has not to be done with respect to irritation or corrosion.