Tetraammonium ethylenediaminetetraacetate

Endpoint summary

Description of key information

The acute oral toxicity data of Na4 EDTA have been used for a estimation of the acute oral toxicity of Tetraammonium EDTA since the pH and not only EDTA may influence the acute toxicity to a certian extend. The pH of Na4EDTA (pH = 10.5-12.5) is almost similar with the pH value of Tetraammonium EDTA ( pH = 9.0 - 9.5), so that a read-across is justified. (For read-across justification also refer to section 13)
The oral LD50 value established for Na4EDTA is 1780 and 1913 mg/kg bw  for females and males, respectively  (BASF, 1983). Concerning the fact, that the test substance Tetraammonium EDTA is a 50 % dilution in water and the pH value is even more neutral it is likely that its LD 50 would exceed a value of 2000 mg/kg bw. This assumption is in line with the results of a range finder study with the test substance itself where a LD 50 value of  > 3940 mg/kg bw  is reported.    
The LOAEC established in an inhalation study with Na2EDTAwas 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.

Additional information

In a study conducted by BASF AG (1983) single doses of 1210, 1780, 2000, 2610 mg/kg bw Na4EDTA were administered by gavage to male and females rats as 12 - 26% solution in water. The dose groups consisted of 10 males and 10 females each which were fasted 16 prior to the experiment. After administration a 14 day observation period followed. The LD50 was found to be between 1780 and 2000 mg/kg bw (1913 males; 1780 females). The clinical symptoms consisted of dyspnea, apathy, ataxia, abnormal positions, spastic gait, exiccosis, diarrhea, shaggy fur, saliva and a poor general state in the higher dose groups additionally diarrhea. At necropsy, findings in the animals that died comprised of redness and/or bloody ulceration of the glandular part of the stomach, redness of the mucous membran of the stomach and gut as well as general hyperemia and bloody mucous content of the gut. No macroscopic abnormalities were observed in the surviving animals at the end of the study.

In a range finder study (DOW, 1962) two rats were fed with a 20 % solution of Tetraammonium EDTA in water at the dose level of 3980 mg/kg bw. No clinical signs were reported. Animals appeared normal during and after feeding. Gross pathology was essentially negative and no mortality occured.

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 dermal toxicity.