Calcium diethyl bis[[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphonate]

Endpoint summary

Description of key information

Acute toxicity, oral, Tif. RAI (SPF) rats (similar to OECD TG 401, adopted 1981): LD50 > 6000 mg/kg bw.
Acute toxicity, oral, Chinese hamster (according to OECD TG 401, adopted 1981): LD50 > 2000 mg/kg bw.
Acute toxicity, inhalation, Tif:RAIf (SPF) rats (equivalent to OECD TG 403, adopted 1981): LC0 > 2350 mg/m³ (aerosol).
Acute toxicity, intraperitoneal,  Tif:RAIf(SPF) rats: LD50 (male/female) = 662 mg/kg bw, LD50 (female) = 735 mg/kg bw, LD50 (male) = 595 mg/kg bw.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

6 000 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

2 350 mg/m³ air

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Acute toxicity, oral

Two studies in hamsters and one study performed in rats are available to assess the acute toxicity of the test substance after single oral administration. In the key study performed similarly to OECD TG 401 (adopted 1981), 5 male and 5 female Tif: RAI (SPF) rats per dose group were administered 1000, 2150, 3590, 4640, and 6000 mg/kg body weight of the test substance (Ciba-Geigy, 1973). No mortality and no gross pathological organ changes have been observed. Within 2 hours after treatment the rats in all dosage groups showed dyspnoea, exophthalmus, curved position and ruffled fur. These symptoms became more accentuated as the dose was increased. The animals had recovered within 6 days. Thus, an LD50 of > 6000 mg/kg bw was deduced.

In a supporting study according to OECD TG 401 (adopted 1981), 5 male and 5 female Chinese hamsters per dose were administered 2000, 5000, and 8000 mg/kg bw test substance (Ciba-Geigy, 1983). Similar mortality rates were observed in all dose groups. The animals died between 6 and 15 days after administration. Clinical signs included dyspnoea, exophthalmus, ruffled fur, curved body position, a sporadic incidence of diarrhoea and transient sedation. Ataxia and tremor were seen only in the high dose group. Gross pathological examinations revealed a decreased testicle size in several males. Due to similar mortality rates in the test groups, no LD50 could be calculated. Thus, the study was repeated with doses of 2000 and 5000 mg/kg bw. The follow up study was equivalent in design to the first study (Ciba-Geigy, 1983). While no mortality was observed in the low dose group, 4/5 male and 2/5 female animals died between 4 and 9 days after administration. Dyspnoea, exophthalmus, sedation, ruffled fur and curved body position were observed in both dose groups. Additionally, diarrhoea and ventral and lateral body position was observed in the high dose group. With the exception of one spotted lung in the high dose group, no gross lesion was found at necropsy. An LD50 > 2000 mg/kg bw was deduced.

Acute toxicity, dermal

No data available.

Acute toxicity, inhalation

In an acute inhalation toxicity study performed equivalently to OECD TG 403 (adopted 1981), 10 male and 10 female Tif:RAIf (SPF) rats were exposed nose-only for 4 h to an aerosol of 2350 mg/m³ test substance (Ciba-Geigy, 1980). No mortality occurred and overall body weights and weight gains were within normal limits when measured at day 7 and 14 of the observation period except the body weight gain for male rats for the interval from 1 to 7 days was reduced when compared to control rats. The surviving animals exposed to the test material recovered within 6 days. After exposure to 2350 mg/m³ animals exhibited slight exophthalmus and curved body positions. Slight to moderate ruffled fur was also noted. Gross necropsies were performed on all animals at the end of the 14 day observation period. No gross pathological changes were noted in the control or in the test groups. Based on these results, the LC50 was determined to be greater than 2350 mg/kg³.

Acute toxicity, intraperitoneal

In a further study 5 male and 5 female Tif:RAIf(SPF) rats were treated with 200, 500, and 1000 mg/kg bw test substance by intraperitoneal injection (Ciba-Geigy, 1983). No mortalities occurred in the low dose group, whereas 2/5 males and 2/5 females died after injection of 500 mg/kg bw. In the high dose group 4/5 males and 3/5 females died. All animals died between 2-3 hours after administration of test substance. Dyspnoea, exophthalmus, ruffled fur, and curved body position were observed in all dose groups. Additionally lateral body position was observed in the high dose group. The surviving animals recovered between 9 and 10 days after administration. No gross lesions were observed after necropsy. Following LD50 have been deduced: LD50 (male/female) = 662 mg/kg bw, LD50 (female) = 735 mg/kg bw, LD50 (male) = 595 mg/kg bw.

Justification for selection of acute toxicity – oral endpoint
near guideline study performed in rats

Justification for selection of acute toxicity – inhalation endpoint
comparable to guideline

Justification for classification or non-classification

Dangerous Substance Directive (67/548/EEC)

- No classification required for acute toxicity

Classification, Labeling, and Packaging Regulation (EC) No. 1272/2008:

- No classification required for acute toxicity