Tetraammonium ethylenediaminetetraacetate

Endpoint summary

Description of key information

No reliable studies on skin or eye irritation with the test substance Tetraammonium EDTA are available.
Since the pH and not only EDTA may influence the irritating properties to a large extend for estimation of the irritating potential of Triammonium EDTA a read-across to Na4EDTA and Na2H2 EDTA was made for assessment. For read.across justification also refer to section 13.
The pH of Tetraammonium EDTA ( pH = 9.0 - 9.5) is in between the pH range of of Na4EDTA (pH = 10.5-12.5) and Na2H2 EDTA (pH = 4-5). 
As Na4 EDTA is not irritating to the skin (BASF, 1982) it is likely that Tetraammonium EDTA is also not irritating to the skin . 
This assumption is in line with results obtained in another skin irritation study conducted with the test substance (DOW, 1962). 
For sodium salts the results for eye irritation vary from not irritating to skin or eye for Na2 EDTA, to irritating to eye for EDTA free acid to risk for serious eye damage after application of Na4EDTA. 
As the irritating effect is influenced by the pH value it is reasonable to assume that the eye irritating effect of (NH4)4 EDTA (pH =  9.0 -9.5 for the 1 %  aqueous solution) is less than the eye irritating effect of the strong alkaline Na4EDTA salt (pH =10.5 - 12.5), but greater than the effect of Na2H2 EDTA (pH = 4-5). 
This assumption is in line with results obtained in a eye irritation study conducted with the test substance (DOW, 1974). 
Therefore it can be concluded the (NH4)4 EDTA might be irritating to the eyes.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

Skin irritation:

A 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 another poorly documented eye irritation study Triammonium EDTA was exposed unchanged to intact and abraded skin of rabbits (DOW, 1962).

The undiluted material was described as essentially non irritating to intact skin.

Eye irritation:

In an eye irritation test performed by BASF (1973)

with Na4EDTA 50 mg were applied to the conjunctival sac of one eye of 2 rabbits. 24 to 72 h after application a mild redness (score 1), mild edema (scale 0.8) and mild opacity (scale 1.3) was present and after 8 days mild redness, mild edema and mild opacity persisted. During all these observation times a grease-like layer was observed.

In another poorly documented eye irritation test Triammonium EDTA (Vertan 675) was tested on rabbits (DOW, 19674).

The sample of Vertan 675 produced moderate pain, slight conjunctival inflammation and slight corneal injury when instilled into a rabbit's eyes

and was described as slightly irritating.

Effects on eye irritation: slightly irritating

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 as Xi, R36 and eye irritant cat 2, respectively, has to be done with respect to irritation or corrosion.