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Description of key information

No studies on the acute toxicity of triammonium hydrogen ethylenediaminetetraacetate are available. Like the sodium salts of EDTA, ammonium salt of EDTA are likely to dissociate at physiological pH to the EDTA anion and the ammonium ion, therefore the acute oral toxicity data of EDTA free acid and its sodium salts have be used for a estimation of acute toxicity triammonium hydrogen EDTA. 
(For read-across justification also refer to section 13).
The acute oral LD50 values were 2500 mg/kg bw (Na2EDTA) and 4500 mg/kg bw (EDTA free acid), respectively.
The LOAEC established in an inhalation study with Na2EDTA was considered to be 30 mg/m³ air.
Furthermore it is highly unlikely that EDTA induced acute dermal toxicity as neither Ca or Na salts of EDTA are able to penetrate the skin.

Key value for chemical safety assessment

Additional information

In the study conducted by BASF AG (1973) single doses of 3200, 4000, 5000, 6400, 8000 and 10000 mg/kg bw edetic acid were administered by gavage to male and females rats as 30% solution in carboxymethyl cellulose solution. The dose groups consisted of 5 males and 5 females each and the animals were observed for 14 days. The LC50 was found to be 4500 mg/kg bw. Clinical symptoms were: squatting posture, aggressiveness, diarrhea and contaminated fur in all dose group. Autopsy of the animals which died revealed acute heart dilatation, bloody ulceration of the stomach and soft to fluid contents of the intestine.

Additionally single doses of 2500, 3200, 4000, 5000 and 6400 mg/kg bw Na2EDTA were administered by gavage to male and female rats as 30% solution in carboxymethyl cellulose solution (BASF, 1973). The dose groups consisted of 5 males and 5 females each and the animals were observed for 7 days. The LC 50 was found to be 2800 mg/kg bw. Clinical symptoms were accelerated respiration, squatting posture, contaminated fur, intermittened respiration, reluctance to move. Autopsy of animals which died revealed dilatation of the heart and stomach as well as diarrhea like content in the gut, congestion of the liver and degeneration of the kidney. The animals which were sacrificed showed no abnormalities during necropsy.

Inhalation route:

In a subacute repeated dose toxicity study (BASF, 2009) 10 male Wistar rats per dose were exposed to a respirable dust aerosol

of Na2H2EDTA

for 6 hours per day for 5 consecutive days at concentrations of 0, 30, 300, 1000 mg/m³ air (also see capter 7.5).

Exposure in the high dose group (1000 mg/m3) was for one day only due to mortality observed. Inhalation exposure to 1000 mg/m³ disodium EDTA for 6 hours caused lethality in 6 out of 20 male rats. Histological examination of the lung of the dead rats revealed congestion, edema, multifocal hemorraghes and inflammatory cell infiltrates.

Inhalation exposure of rats to disodium EDTA for 6 hours per day, 5 consecutive days cause concentration dependant lesions in the larynx and lungs that were fully reversible within 14 days. Due to histopahological changes in the low dose group a no observed effect level could not be determined.

The LOAEC was considered to be 30 mg/m³ air.

Justification for classification or non-classification

Based on the results of a repeated dose toxicity study (5 consecutive days, see 7.5.3) a classification as harmful by inhaltion (Xn, R20) and Acute Toxicity Inhalation Cat. 4 (H332, harmful if inhaled) is done according to Council Directive 67/548/EEC and CLP, respectively.

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 acute oral and dermal toxicity.