Tetrapotassium ethylenediaminetetraacetate

Endpoint summary

Description of key information

The acute oral LD50 of EDTA 4K was found to be > 1780 — < 2000 mg/kg bw, based on the read across on EDTA 4Na (BASF 1983).

A LOAEC value of 30 mg/m³ air was established in a subacute range finder toxicity study with Na2H2EDTA, which here is also suitable to assess acute toxicity. This value was extrapolated to EDTA 4K for the read across.

Additional information

Oral route:

In the key 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 LC50 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 membrane 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.

Several other acute LD50 values in rat have been determined. A study by BASF (1982) reported an oral LD50 of ca 1700 mg/kg bw in rats (males 2150; females >1210 - <1780 mg/kg bw). In these study groups consisting of 5 males and 5 females Na4EDTA was administered by gavage with 1210, 1780, 2610, 3830 mg/kg bw of a 12 - 38% solution in water. After administration a 14 day observation period followed. The clinical symptoms and pathological findings were identical to the key study performed one year later. In two prior oral LD50 determinations which were conducted the same way oral LD 50 values of 2700 mg/kg bw (BASF 1970) and 1700 mg/kg bw (BASF, 1978) were reported.

A study by Ciba-Geigy several groups of 5 rats per sex and dose were treated simultaneously by gavage with preparations of the test substance in 2% carboxymethyl cellulose (1470, 2150, 2400, 3170, 3590 mg/kg bw). After administration rats were observed for 7 days. The LD50 was found to be 2580 mg/kg bw (2390 - 2780 mg/kg bw). Clinical symptoms were sedation, dyspnoea, exophthalmus, curved position and ruffled fur. Additionally in the two highest dosage groups, chromodacryorrhoea and diarrhea were observed. However during necropsy nothing abnormal was observed.

An additional study by BASF was performed with a 40% Na4EDTA solution in water (Trilon B liquid). In this study groups consisting of 5 males and 5 females were administered by gavage with 3160, 4640, 6810, 10000 mg/kg bw of a 12 - 38% solution of in water. After administration a 14 day observation period followed. The oral LD50 was reported to be 3200 mg/kg bw. The clinical signs were dyspnoe, apathy, aggressiveness, prone position, ataxia, tremor, spastic gait, convulsions, exsicosis, saliva and a generally bad state.

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 the oral toxicity study a classification as Xn, R22 and Acute Toxicity Cat. 4 (oral) is done according to Council Directive 67/548/EEC and CLP, respectively.

A classification has not to be done

taking into account the provisions laid down in Council Directive 67/548/EEC and CLP, with respect to acute dermal toxicity.

Based on the results of a repeated dose toxicity study (5 consecutive days, see chap. 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.