Nickel Cobalt Manganese Hydroxide

Endpoint summary

Description of key information

Oral

The acute oral toxicity of pNMC hydroxide (8:1:1) was investigated in the Sprague-Dawley CD strain rat in a study which was conducted under GLP conditions and in accordance with the standardised guidelines OECD 423 and Commission Regulation (EC) No 440/2008 of 30 May 2008, B.1.Tris) in Crl:WI Wistar rats.

Two groups of 3 female Crl:WI rats were treated with the test item at dose level of 300 mg/kg body weight (bw) and two groups of 3 females were treated at the dose level of 2000 mg/kg bw. A single oral treatment was carried out by gavage for each animal after an overnight food withdrawal. Food was made available again 3 hours after the treatment. The test item was formulated in 1% methyl cellulose at concentrations of 30 and 200 mg/mL at a dose volume of 10 mL/kg bw, respectively.

Initially three females were treated at a dose level of 300 mg/kg bw. All animals survived, therefore the second group of animals were treated at a dose level of 300 mg/kg bw. No mortality was observed, therefore the third group of animals were treated at a dose level of 2000 mg/kg bw. All animals survived, the dose of 2000 mg/kg bw were repeated with 3 additional animals.

Clinical observations were performed at 30 minutes, 1, 2, 3, 4 and 6 hours after dosing and daily for 14 days thereafter. Body weight was measured on Days -1, 0, 7 and 14 (before necropsy). All animals were subjected to a necropsy and a macroscopic examination.

Results: There was no mortality at dose levels of 300 and 2000 mg/kg bw. After treatment at 300 and 2000 mg/kg bw, all animals were symptom-free from Day 0 until the end of the 14-Day observation period. There were no effects on body weight or body weight gains at dose levels of 300 and 2000 mg/kg bw. There was no evidence of the macroscopic observations in animals dosed at 300 and 2000 mg/kg bw and subjected to the necropsy on Day 14.

Conclusion: Under the conditions of this study, the acute oral LD50 value of the test item pNMC hydroxide (8:1:1) was found to be greater than 2000 mg/kg bw in female Crl:WI rats.

 

 

Inhalation

Information on the acute inhalation toxicity of pNMC hydroxide (8:1:1) in male and female Crl:WI Wistar rats was generated in a single 4h-nose-only exposure at the maximum achievable concentration, following OECD N° 403. EU Method B.2 and EOA OPPTS 870.1300. Since the target concentration of 5 mg/L was not technically feasible, the maximum achievable concentrations was 0.09 mg/L in the main study during the animal exposures following the OECD TG 403. The mass median aerodynamic diameters (MMAD) was 3.70 µm with geometric standard deviation (GSD) of 5.77.

Based on the results of a Sighting Exposure with two animals of both sexes (maximum achievable concentration of 0.08 mg/L), the main study with five male and five female rats was performed at the target concentration of 0.09 mg/L. Animals were exposed to the test atmosphere for 4 hours using a nose-only exposure system. Aerosol concentration was measured gravimetrically 17 times in the Sighting Exposure and in the main study during each 4-hour exposure and the particle size distribution of the test aerosol was determined 3 times. The day of exposure was designated as Day 0 followed by a 14-day observation period. Clinical observations were performed on all animals during exposure at hourly intervals, following removal from restraint, approximately 1 hour after exposure, and daily for 14 days thereafter. Body weight was measured on Days 0 (before the exposure), 1, 3, 7 and 14. Gross necropsy was performed on all animals on Day 14.

 

Results: No mortality occurred during the study. Furr staining by test item (on the head and nose), red-brown staining (on the area around eyes) and wet fur (on the whole body) were observed from Day 0 up to Day 6. All animals (male, female) were symptom-free from Day 7. Red-brown staining (as chromodacryorrhea), fur staining by test item and wet fur in the animals were considered to be related to the restraint and exposure procedures or discomfort of the animals but not to be toxicologically significant. Slight to moderate body weight losses were recorded on Days 0-3. The body weight gains were normal between Days 3-14. There was no evidence of any test item-related gross changes at necropsy in any animal.

Conclusion: Under the experimental conditions of this study, no mortality occurred when exposed to a test atmosphere concentration of 0.09 mg/L as a maximum achievable concentration for 4 hours. The acute inhalation median lethal concentration (LC50) of pNMC hydroxide (8:1:1) in male and female Crl:WI rats was therefore considered to be above 0.09 mg/L.

 

Dermal

 

The effects assessment on the acute dermal toxicological properties of pNMC hydroxide is based on the toxicological properties of its constituents (hydroxide forms of Mn, Co, Ni) (Assessment Entity Approach).

A reliable assessment, based on the CLP mixture rules and using the MeClas Classification Tool, was conducted on a generic pNMC hydroxide sample (composition based on worst-case concentrations for each constituent, as defined in IUCLID section 1.2). According to MeClas, there is no need for the classification of the assessed generic pNMC hydroxide composition for the acute dermal endpoint.

 

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

> 2 000 mg/kg bw

Justification for classification or non-classification

The following information is taken into account for any hazard / risk assessment:

Oral: LD₅₀> 2000 mg/kg bw, rat (female), OECD 423, EU Method B.1 bis, Sanders (2007a)

Inhalation:LC₅₀> 0.09 mg/L (maximum achievable concentration)n rat, OECD 403; EU Method B.2

Dermal: LD₅₀> 2000 mg/kg bw, rat (male/female),MeClas calculation

 

Value used for CSA:

• Acute oral toxicity: No adverse effect observed

• Acute inhalation toxicity:No adverse effect observed

• Acute dermal toxicity: No adverse effect observed

 

 

Justification for classification or non-classification

In accordance with the criteria for classification as defined in Annex I, Regulation (EC) No. 1272/2008, the tested substance requiresnoclassification with respect tothe variousacute toxicityexposure routes.