Zinc bis(diethyldithiocarbamate)

Endpoint summary

Description of key information

Acute oral toxicity of zinc bis(diethyldithiocarbamate) (ZDEC) has been investigated in several studies with rats, all predating GLP and OECD guidelines. The lowest obtained LD50 value was 1960 mg/kg bw in male rats. Acute dermal toxicity study with rabbits resulted in LD50 > 2000 mg/kg bw. No data on acute inhalation toxicity were available; however, as sufficient data are available on the other two routes of exposure, the study is not warranted in accordance with Column 2 of REACH Annex VIII.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 960 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Additional information

Several acute oral toxicity studies with zinc bis(diethyldithiocarbamate) (ZDEC) were available for assessment, all predating GLP and OECD Guidelines. Most of them (TNO, 1976a; Pharmacology Research Inc., 1977; Younger Laboratories, 1976) reported LD50 values in rats ranging from 2450 to 3530 mg/kg bw; however, the study of Sumimoto Chemical Co., Ltd., 1977 reported lower values of 2280 mg/kw bw for female and of 1960 mg/kg bw for male rats, respectively. Two studies (TNO, 1976a; Pharmacology Research Inc., 1977) reported possible renal pathology, with necrotic spots on the kidneys of several animals (TNO, 1976a). No significant changes at necropsy were noted in the study of Sumimoto Chemical Co., Ltd., 1977. Clinical signs included mostly diarrhea, reduced appetite and activity and weight losses. Using the precautionary principle, the lowest LD50 value shall be used for risk assessment.

In the available acute dermal toxicity study with rabbits (Pharmacology Research, Inc., 1977) a single dose of 2000 mg/kg bw of ZDEC was applied to pre-moistened hair-clipped skin of each of the 6 rabbits under occlusive dressing. The patch was removed 24 hours post-dosing and animals were observed for 7 days. No mortalities were observed and the animals remained asymptomatic during the observation period. Based on the result of the study, dermal LD50 in rabbits was established to exceed 2000 mg/kg bw.

No data on acute inhalation toxicity of zinc bis(diethyldithiocarbamate) (ZDEC) were available for assessment. However, in accordance with Column 2 of REACH Annex VIII the study does not need to be conducted, as sufficient data are available on the other two routes of exposure.

Justification for classification or non-classification

Based on the acute oral LD50 value of 1960 mg/kg, zinc bis(diethyldithiocarbamate) (ZDEC) should be classified as harmful if swallowed (Xn, R22) and Category 4, H302 (harmful if swallowed) according to the EU Directive 67/548/EEC and EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008, respectively. Based on the acute dermal LD50 value of > 2000 mg/kg, classification for acute dermal toxicity is not warranted according to the EU Directive 67/548/EEC and EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.