AS NZS 8124.12:2017 pdf free.Safety of toys Part 12: Determination of total concentration of certain elements in toys (ISO 8124-5:2015, MOD).
6.2 Compositing of test portions
Up to three test portions can be combined to form a composite test portion provided that the required detection limit can still be achieved (see A.1.2, practical considerations in deciding whether to composite test portions) and the combined materials are similar in nature.
The compositing of dissimilar materials is not permitted, e.g. compositing textiles and paint coatings. When calculating the concentration of a target element in a material, it is assumed that all of that element found in the digested sample originated from any one of the composited materials. Using this assumption and the masses of the individual materials, the total concentration of the target element is calculated for each individual material in the composite test portion.
7 Preparation of test portions
Materials from the laboratory sample are selected for testing in accordance with Clause 6 (selection and composition of test portion) and removed using cutting tools such as scalpels, razor blades, scissors, and grinding and milling tools as described in the subclauses below. If a grinding apparatus [such as a mill (5.2.4) or rotary grinding tool (5.2.5) with disposable grinding bits] is used, then any contaminated parts shall be thoroughly cleaned or disposed of between uses to prevent cross-contamination. Ensure that the device itself cannot contaminate the material being prepared.
In 21 to 29. collect sufficient material to obtain a test portion of between 10 mg and 100 mg. In cases where less than 10 mg of material is available (see 6.1, selection of test portions) no further testing is required and this is reported under ClauseJZl c) (test report).
Digest the prepared test portion according to the procedures described in &1 (microwave digestion) or &Z (hot plate and hot block digestion of test portion).
7.1 Coatings of paint, varnish, lacquer, printing ink, polymer and similar coatings
Remove each different coating from the laboratory sample by scraping down to the base material, taking care to avoid the inclusion of the base material. Where lithographic coatings (dot printing) are present, it is impractical to separate the individual colours and so remove these coatings in such a way that a representative test portion is obtained.
For some coatings deposited on a non-polymeric base material, it is permissible to add a few drops of solvent, such as acetone/ethanol (5.1.7) mixture or methylene chloride (5.1.6), to soften the paint and aid in its removal from the base material.
In the first instance, acetone/ethanol (5.1.7) should be used. If this treatment is not effective in aiding removal, methylene chloride can be used under a fumes hood.
If a solvent treatment is used, ensure that all traces of solvent have been removed by evaporation prior to microwave digestion (see 81, microwave digestion). Divide removed coatings into small pieces having a maximum length in any direction of 2 mm in order to facilitate efficient digestion.AS NZS 8124.12 pdf download.