Copper sulphide

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Already evaluated by the Competent Authority for Biocides and Existing Substances Regulations.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Copper oxide

EC Number:

215-269-1

EC Name:

Copper oxide

Cas Number:

1317-38-0

Molecular formula:

CuO

IUPAC Name:

copper(II) oxide

Details on test material:

Lot/Batch number: 02-0084
Description: Brown/black powder
Purity: 97.7% cupric oxide
Stability: Stable at room temperature
Molecular formula: CuO
Molecular weight: 79.55
Smiles notation: O=[Cu]
InCHI: 1s/Cu.O

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Details on test animals or test system and environmental conditions:

Source: Charles River (UK) Ltd, Margate, Kent, UK
Age/weight at study initiation: Test animals were at least 200 g and were approximately 8 weeks old.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

arachis oil

Details on oral exposure:

Concentration in vehicle: 200 mg/ml
Total volume applied: 10 ml/kg

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

3 animals (2 groups both dosed 2000 mg/kg bw)

Control animals:

no

Details on study design:

Clinical observations, mortality, bodyweights and necropsy.
Observations for death or toxicity were taken 0.5, 1, 2 and 4 hours after dosing and then once daily for fourteen days. Individual bodyweights were
measured prior to dosing and seven and fourteen days after treatment. All animals were subjected to gross pathological examination after death.

Statistics:

LD50 was determined from mortality data and not by statistical analysis.

Results and discussion

Effect levels

Sex:

male

Dose descriptor:

LD50

Effect level:

> 2 500 mg/kg bw

Based on:

test mat.

Mortality:

There were no mortalities among any of the treated animals at study termination.

Clinical signs:

other: There were no signs of systemic toxicity at any observation time point in any of the treated animals.

Gross pathology:

No abnormalities were noted at necropsy.

Any other information on results incl. tables

There were no mortalities or signs of systemic toxicity among any of the animals treated with copper oxide at the test concentration of 2000 mg/kg b.w. An LD₅₀of >2500 mg/kg b.w can be estimated using the flow chart in annex 2d of OECD Guidelines for the Testing of Chemicals No. 423 “Acute Oral Toxicity – Acute Toxic Class Method” (adopted 17 December 2001).

Justification of the read-across from copper (II) oxide to copper sulphide:

In order to minimise animal testing, available data on copper(II) oxide have been read-across to copper sulphide (copper (II) oxide is unclassified on the basis of acute toxicity, irritation and sensitisation potential). These are both simple inorganic copper(II) compounds with very low water solubility and an anion of no toxicological concern. In fact, theoretical estimates for the solubility of copper sulphide are orders of magnitude lower than those of the oxide, ranging from 3.31E-11 µg/L to 2.4E-10 µg/L (see the attached document "The Solubility Products of Copper Sulphide" for further information). It is generally accepted that lower water solubility can be equated to lower bioavailability and hence acute toxicity; an effect clearly seen by a comparison of copper(II) oxide toxicity with that of the more soluble copper(I) oxide. On this basis, it is considered that a read-across of the acute toxicological, irritation and sensitisation properties from copper(II) oxide to copper sulphide represents a reasonable worst-case approach, and leads to that conclusion that copper sulphide is similarly unclassified. This conclusion is supported by the fact that acute oral and irritation testing carried out with dicopper sulphide confirms that this marginally more soluble compound is also unclassified.

 

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

An LD50 of >2500 mg/kg b.w can be estimated using the flow chart in annex 2d of OECD Guidelines for the Testing of Chemicals No. 423 “Acute Oral Toxicity – Acute Toxic Class Method” (adopted 17 December 2001).
Classification according to Directive 67/548/EEC: Not classified.
Classification according to CLP/GHS: Not classified.

Executive summary:

Materials and Methods:

The study was performed to assess the acute oral toxicity of copper oxide following a single oral administration by gavage in the Sprague-Dawley rat. A group of three fasted ma   le rats were treated with the test material at a dose level of 2000 mg/kg bw administered as a suspension in Arachis oil BP. This was followed by a further group of three fasted males treated with the same dose level.

The animals were observed for deaths or overt signs of toxicity at 0.5, 1, 2 and 4 hours after dosing and subsequently once daily for 14 days. The individual bodyweights were recorded prior to dosing, 7 and 14 days after treatment. At the end of the observation period, the animals were sacrificed and subject to gross pathological examination.

The study was conducted according to OECD Guidelines for the Testing of Chemicals No. 423 “Acute Oral Toxicity – Acute Toxic Class Method” (adopted 17 December 2001). The study was also conducted according to GLP.

No deviations from the test guidelines, or deficiencies in the method were reported.

Results and Discussion:

There were no mortalities or signs of systemic toxicity among any of the animals treated with copper oxide at the test concentration of 2000 mg/kg b.w. All animals showed expected gains in bodyweight over the study period and there were no abnormalities noted at necropsy.

An LD50of >2500 mg/kg b.w can be estimated using the flow chart in annex 2d of OECD Guidelines for the Testing of Chemicals No. 423 “Acute Oral Toxicity – Acute Toxic Class Method” (adopted 17 December 2001).

The test material does not meet the criteria for classification.