L-Aspartic acid, N,N'-1,2-ethanediylbis-

Endpoint summary

Description of key information

No acute toxicity data in humans were identified. 
In a GLP study carried out according to OECD Guideline 423 (and EU Method B.1), the acute oral LD50 for EDDS acid was determined to be greater than 2 g/kg bw in male and female rats following gavage administration (Brunt, 2002a). In addition, in GLP studies conducted according to OECD Guideline 401 (available at the time), acute oral LD50 values of >2 g/kg bw (Mahl, 1993a) and >2.7 g/kg bw (Kynoch et al. 1989) have been determined for trisodium EDDS in male and female rats following gavage administration. 
In a GLP study conducted according to OECD Guideline 403 (available at the time), an acute inhalation 4-h LC50 value of >1.49 mg/L (about 1490 mg/m3; the highest attainable concentration) in air was determined for trisodium EDDS in male and female rats following whole body exposure (Hardy and Jackson, 1989).
In GLP studies conducted according to OECD Guideline 402 (available at the time), acute dermal 24-h LD50 values of >2 g/kg bw (Mahl, 1993b) and >2.64 g/kg bw (Liggett and Allan, 1989) have been determined for trisodium EDDS in male and female rabbits and rats, respectively, following semi-occlusive application. 

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Dose descriptor:

LC50

Value:

1 490 mg/m³ air

Acute toxicity: via dermal route

Endpoint conclusion

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

No acute toxicity data in humans were identified.

In a GLP study carried out according to OECD Guideline 423 (and EU Method B.1), three male and three female Sprage-Dawley rats were given a single dose of 2 g/kg bw EDDS acid via oral gavage. Rats were observed for overt signs of toxicity ½, 1, 2 and 4 hr following dosing, then once daily for fourteen days. Body weight was recorded prior to dosing (day 0), then on days 7 and 14. All animals were sacrificed after 14 days, and were subject to external and internal gross pathological examination. The occurrence of any macroscopic abnormalities was recorded. No deaths or overt signs of systemic toxicity were observed throughout the experiment. Following sacrifice and examination of major organs on day 14, no macroscopic abnormalities were observed. All animals gained weight over the study period as expected. In conclusion, the acute oral LD50 for EDDS acid was determined to be greater than 2 g/kg bw in male and female rats (Brunt, 2002a). In addition, in GLP studies conducted according to OECD Guideline 401 (available at the time), acute oral LD50 values of >2 g/kg bw (Mahl, 1993a) and >2.7 g/kg bw (Kynoch et al. 1989) have been determined for trisodium EDDS in male and female rats following gavage administration.

In a GLP study conducted according to OECD Guideline 403 (available at the time), the acute inhalation toxicity of trisodium EDDS was assessed in a study on male and female rats. Groups of five rats of each sex were exposed continuously (by whole body contact) for 4 h to air containing 0 or 1.49 mg trisodium EDDS/L (about 1490 mg/m3; the highest attainable concentration with the equipment used). The animals were then observed for a 14-day period for mortality, clinical signs of toxicity and changes in body weight before being examined macroscopically for gross abnormalities and for differences in the lung, liver and kidney weights compared to the control groups. No deaths occurred during the study and no clinical signs of toxicity were evident. Although eye squint, salivation and restless behaviour were observed during the treatment period (consistent with exposure to an irritant dust) these had disappeared within 1 h post-treatment. The test substance remained on the fur of the exposed groups. Body weights were not significantly different compared to the control groups; at necropsy there were no abnormal findings and the lung, liver and kidney weights were comparable to those of the controls. An acute inhalation 4-h LC50 value of >1.49 mg/L (about 1490 mg/m3) in air was determined for trisodium EDDS in male and female rats following whole body exposure (Hardy and Jackson, 1989).

In a GLP study conducted according to OECD Guideline 402 (available at the time), the acute dermal toxicity of trisodium EDDS was assessed in male and female New Zealand White rabbits. The test powder (2.64 g/kg bw) was applied to the clipped backs of five rabbits of each sex, moistened with water to aid adhesion to the skin and covered with a semi-occlusive dressing for 24 h. The test substance was subsequently removed by washing in warm water and blotting dry. The animals were observed for 14 days for mortality, clinical signs of systemic toxicity, irritation of the application area and body weight changes, after which they were killed and the organs of the thoracic and abdominal cavities were examined macroscopically. No clinical signs of toxicity were seen in any of the animals and no deaths occurred during the 14-d observation period. Diarrhoea, lasting about 2 days in three animals of each sex was not considered to be treatment-related. At necropsy, no gross changes in organs or tissues were detected. An acute dermal 24-h LD50 value of >2640 mg/kg bw was determined for trisodium EDDS in male and female rabbits (Liggett and Allan, 1989). In a GLP study conducted according to OECD Guideline 402 (available at the time), trisodium EDDS was studied for acute toxicity after single, semi-occlusive, application to the shaved backs of 5 male and 5 female Wistar rats. The test substance was applied as an aqueous suspension at a dose of 2000 mg/kg bw for 24 h, and was subsequently removed by washing in warm water. The animals were observed for 14 days for mortality, clinical signs of systemic toxicity, irritation of the application area and body weight changes, after which they were killed and the organs examined macroscopically. No deaths were seen, and none of the animals showed signs of toxicity during the 14-day observation period. No treatment-related effects on body weight gain were reported, and no irritation at the site of application was observed. At necropsy, no organ abnormalities were evident in the rats upon macroscopic examination. An acute dermal 24-h LD50 value of >2000 mg/kg bw was determined for trisodium EDDS in male and female rats (Mahl, 1993b).

[Data on trisodium EDDS is considered relevant to use for understanding the potential acute toxicity of EDDS acid, and is acceptable for using as read-across information.]

Justification for classification or non-classification

According to EU CLP and DSD regulations, EDDS acid (and its trisodium salt) would not be classified as acutely toxic by the oral, inhalation or dermal routes under the conditions of the tests described.