Standard for cuprous oxide active constituent (marine coatings and antifouling paints)

Version: 
2
Effective Date: 
30 May 2016
1. Description: 

the material shall consist of cuprous oxide [copper (I) oxide, Cu2O] together with related manufacturing impurities and shall be an orange to red to purple powder, free from visible extraneous matter and added modifying agents other than stabilisers, and being a constituent of a marine coating or antifouling paint.

2. Common Name: 
Cuprous oxide - for use in marine coatings and antifouling paints
3. Chemical Name (IUPAC): 

Copper (I) oxide

4. CAS Number: 
1317-39-1
5. Identity test: 
identity of the copper ion must be established by atomic absorption spectroscopy or inductively coupled plasma spectroscopy or colorimetric method or any other suitable test method.
6. Composition: 

6.1. Active constituent:

Cuprous oxide content: 900 g/kg minimum (equivalent to no less than 800 g/kg total copper) and when determined the content obtained shall not differ from that declared by more than ± 30g.

6.2.Impurities:

Arsenic (As): maximum 0.2 × X = mg/kg. Where X is the copper content (g/kg) found under 6.1 (Note 1).

Lead (Pb): maximum 5 × X = mg/kg. Where X is the copper content (g/kg) found under 6.1 (Note 2).

Cadmium (Cd): maximum 0.2 × X = mg/kg. Where X is the copper content (g/kg) found under 6.1 (Note 3).

Copper other than cuprous oxide:

Metallic copper: maximum 50 × X = mg/kg. Where X is the copper content (g/kg) found under 6.1 (Note 4).

Cupric copper: maximum 100 × X = mg/kg. Where X is the copper content (g/kg) found under 6.1 (Note 5).

Copper soluble in water: maximum 25 × X = mg/kg. Where X is the copper content (g/kg) found under 6.1 (Note 6).

6.3 Other impurities and impurities of toxicological significance:

Information on impurities that are or may be present in the active constituent at levels of greater than or equal to 0.1% or 1 g/kg must be provided. Note that toxicological significant impurities at any level must be characterised and reported. The submission with respect to impurities must include structural formulae and possibly a scheme for the formation of the impurity, followed by a text discussion of its formation. This may include the sources of the Copper, for example recycled copper wire that has been incinerated to remove the insulation.

Note 1: On a found content of 800 g/kg total copper, the maximum permitted amount of arsenic would be 0.2 × 800 = 160 mg/kg in the technical material.

Note 2: On a found content of 800 g/kg total copper, the maximum permitted amount of lead would be 5 × 800 = 4 000 mg/kg in the technical material.

Note 3: On a found content of 800 g/kg total copper, the maximum permitted amount of cadmium would be 0.2 × 800 = 160 mg/kg in the technical material.

Note 4: On a found content of 800 g/kg total copper, the maximum permitted amount of metallic copper would be 50 × 800 = 40 000 mg/kg or 40 g/kg in the technical material.

Note 5: On a found content of 800 g/kg total copper, the maximum permitted amount of cupric copper would be 100 × 800 = 80 000 mg/kg or 80 g/kg in the technical material.

Note 6: On a found content of 800 g/kg total copper, the maximum permitted amount of copper soluble in water would be 25 × 800 = 20 000 mg/kg or 20 g/kg in the technical material.

 

 

    7. Analytical methods: 
    • The analytical method used for the determination of the active constituent and toxicological significant impurities must be validated in accordance with the APVMA guidelines for the validation of analytical methods
    • The APVMA guidelines on validation of analytical methods state that 'Analytical methods described in CIPAC handbooks and AOAC International Manual, and in recognized pharmacopoeias [BP, BP (Vet), Ph Eur and USP] for a particular active constituent or formulation are regarded as validated and do not require revalidation'. However, the suitability of these methods must be verified under actual conditions of use ie, the selectivity and accuracy of the method should be demonstrated for the published method when applied to the relevant sample matrix and laboratory conditions.
    • When a CIPAC or AOAC method is used for the assay of an active constituent in a bulk active constituent, there is no matrix. The registrants need to check the specificity of the method to ensure there is no interference from impurities or degradation products. However, determination of accuracy of the method is not required as there is no potential for the product matrix to have an effect on the determination of the active constituent. However, when a CIPAC or AOAC method is used for the assay of an active constituent in a formulated product, determination of both specificity and accuracy is required as the matrix is relevant in formulated products (formulated products have different composition and quantities of excipients).
    • Unless the scope of the collaborative method (CIPAC and AOAC) also includes toxicologically significant impurities in the active constituent, validation data for impurities are required.

     

     

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