Nickel difluoride

Endpoint summary

Description of key information

ACUTE ORAL TOXICITY: An LD50 for acute oral toxicity of 310.2 mg NiF2*4H2O has been identified from the Eurofin 2008 study. This value correseponds to 178 mg/Kg bw of Nickel fluoride anhydrous

ACUTE INHALATION TOXICITY: An LC50 for acute inhalation toxicity of 2.48 mg NiSO4.6H2O/L air for males and females has been identified from the EPSL 2009  study. This value corresponds to 0.91 mg/L of Nickel Fluoride, i.e. 910 mg/m3

ACUTE DERMAL TOXICITY: No proper acute dermal studies with nickel sulphate have been found. Nickel sulphate was tested on volunteers in 1979 and a 20% water solution resulted as irritant. New testing by the dermal route has been waived as described below and under Section 7.2.3 of IUCLID.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

178 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Dose descriptor:

LC50

Value:

910 mg/m³

Additional information

An LD50 for acute oral toxicity of 310 mg NiF2.4H2O from Eurofin 2008 study is used for the risk characterisation.

A background document describing the use of Ni sulfate as a source substance for read-across to other nickel compounds has been attached to Section 7.2.1 of IUCLID. 

An LC50 for acute inhalation toxicity of 2.48 mg NiSO4.6H2O/L air for males and females has been identified from the EPSL 2009 study. A background document describing the use of Ni sulfate as a source substance for read-across to other nickel compounds for acute oral and acute inhalation toxicity has been attached to Section 7.2.2.

There are no available data on which to evaluate acute dermal toxicity. However, acute toxicity is expected to be low in view of the poor absorption by this route. In addition, please note the following in regards to REACH endpoint requirements identified in Column 2 of the REACH Annex VIII which state,

"in addition to the oral route (8.5.1), for substances other than gases, the information mentioned under 8.5.2 to 8.5.3 [inhalation and dermal acute toxicity] shall be provided for at least one other route. The choice for the second route will depend on the nature of the substance and the likely route of human exposure. If there is only one route of exposure, information for only that route need be provided”.  The rules for adaptation also state that, “Testing by the dermal route is appropriate if…(1) inhalation of the substance is unlikely…”.  

As oral and inhalation routes of exposure are more relevant and data for these have been provided, testing for acute dermal toxicity is therefore waived based on this information.

FOR AN EXTENSIVE DISCUSSION, REFER TO THE NICKEL SULFATE DOSSIER WHICH IS BASED ON THE CONCLUSIONS EXPLAINED IN THE 2008/2009 EUROPEAN UNION EXISITING SUBSTANCE RISK ASSESSMENT OF NICKEL (EU RAR) (EEC 793/93)

Justification for classification or non-classification

Acute oral toxicity

A newly conducted GLP OECD guideline compliant study reported an LD50 =310 mg/kg for Ni fluoride tetrahydrate, which corresponds to 178 mg/kg bw of Nickel fluoride anhydrous: The classification for acute oral toxicity as Xn; R23 and Acute Tox. 3; H301. 

 

Acute inhalation toxicity

As data were not available at the time of classification, the EU Risk Assessment based the classification for acute inhalation toxicity on read-across from the oral data. However, a newly conducted GLP OECD guideline compliant study reported an LC50 =2.48 mg/L for Ni sulfate hexahydrate as aerosolised dust. This value corresponds to LC50=0.91 mg/L for nickel fluoride anhydrous. This value is used to justify the classification as T: R25 and Acute Tox. 3: H331 for acute inhalation toxicity.

Acute dermal toxicity

There is no data on toxicity following cutaneous administration. Dermal absorption is expected to be very limited. Therefore, this endpoint is not considered in the risk characterisation and no classification for acute toxicity via the dermal route is proposed.

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