Nickel oxalate

Direct observations: clinical cases, poisoning incidents and other

Administrative data

Endpoint:

direct observations: clinical cases, poisoning incidents and other

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Meets generally accepted scientific standards with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

The chamber scarification test for irritancy

Author:

Frosch PJ and Kligman AM

Year:

1976

Bibliographic source:

Contact Dermatit., 2:314-324

Materials and methods

Study type:

study with volunteers

Endpoint addressed:

skin irritation / corrosion

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

In a study performed to develop a new test for skin irritancy, nickel sulphate was included as one of the test agents. A volume of 0.1 mL of nickel sulphate in various concentrations was pipetted on to a disc of two thicknesses of non-woven cotton cloth. The disc was mounted in a chamber designed for use in tests of contact sensitisation, which was sealed to the skin with non-occlusive tape or Dermicel. The advantage of the chamber compared with the use of patches was that there was no loss of test material and uniform contact with the skin. The test subjects were groups of 5-10 light-skinned, young Caucasians. The test material was applied on the mid-volar forearm once daily for 3 days with readings made at 72h, 30 min after removal. The test was conducted on both intact and scarified skin. The reactions were graded on a five-point scale from 0 to 4 (1: erythema, 2: increased erythema, 3: severe erythema with partial confluency with or without other lesions, 4: confluent severe erythema sometimes associated with oedema, necrosis or bulla formation).

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Nickel sulphate

EC Number:

232-104-9

EC Name:

Nickel sulphate

Cas Number:

7786-81-4

IUPAC Name:

nickel(2+) sulfate

Details on test material:

- Name of test material (as cited in study report): Nickel sulphate
- Molecular formula (if other than submission substance): NiSO4
- Molecular weight (if other than submission substance): 154.768
- Smiles notation (if other than submission substance): S(=O)(=O)([O-])[O-].[Ni+2]
- InChl (if other than submission substance): InChI=1/Ni.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2
- Substance type: no data
- Physical state: no data
- Analytical purity: no data

Method

Type of population:

general

Subjects:

Five to 10 volunteer, light-skinned, young adult Caucasoids constituted a test panel. For very discriminating work "hyper-reactors" were selected; these persons were especially vulnerable to irritants and could be identified by a simple test, namely, elicitation of a brisk inflammatory reaction (severe erythema with edema and tiny vesicles)
by a 24-hour forearm chamber exposure to 5 % aqueous sodium lauryl sulfate.

Ethical approval:

not specified

Route of exposure:

dermal

Reason of exposure:

intentional

Exposure assessment:

measured

Details on exposure:

A volume of 0.1 ml of nickel sulphate in various concentrations was pipetted on to a disc of two thicknesses of non-woven cotton cloth. The disc was mounted in a chamber designed for use in tests of contact sensitisation, which was sealed to the skin with non-occlusive tape or Dermicel. The advantage of the chamber compared with the use of patches was that there was no loss of test material and uniform contact with the skin. The test material was applied on the mid-volar forearm once daily for 3 days with readings made at 72h, 30 min after removal. The test was conducted on both intact and scarified skin.

Examinations:

The reactions were graded on a five-point scale from 0 to 4 (1: erythema, 2: increased erythema, 3: severe erythema with partial confluency with or without other lesions, 4: confluent severe erythema sometimes associated with oedema, necrosis or bulla formation).

Results and discussion

Results of examinations:

The sensitivity of the assay on scarified skin was compared with the sensitivity on normal skin. No details of the results on normal skin are shown. The threshold concentration to produce “just an irritation reaction in 3 days” on normal skin was 20.0% while on scarified skin it was 0.13%. The ratio of threshold concentration on normal skin and threshold concentration on scarified skin was 154. This was the highest ratio among the substances tested, which included surfactants, inorganic salts, antimicrobials, and acids.

Applicant's summary and conclusion

Conclusions:

This study demonstrated skin irritation for nickel sulphate with a threshold of 20% on healthy skin.