Development of guidelines for the control of lead content in paint and varnishes

Abstract

Introduction. Determination of low concentrations of lead in paint and varnishes is one of the actual problems in ensuring the safety of these products. The requirements set out in the draft Technical Regulation of the Eurasian Economic Union «on the Safety of Paint and Coating Materials» for a standard of 0.009% lead on a dry weight basis stipulate the availability of precision methods for determining lead in paint and varnishes with low detection limits. Materials and methods. Nine different types of paint samples were selected as test objects. The study was carried out by atomic absorption spectrometry with electrothermal atomisation with pre-microwave sample preparation. Paint samples were preliminarily applied on a sheet of sanded FC plywood, dried and taken from the surface with a spatula in the form of fine shavings. The absolutely dry chips were microwaved, centrifuged to separate the undecomposed sludge and analysed. The efficiency of the developed approach was proven by validating the method on 20 model samples of one of the paint types investigated. Results. Validation of the proposed method of lead determination in paints gave satisfactory results in terms of recovery rate and repeatability, so it can be concluded that the method is suitable for the solution of the posed analytical problem. Having analysed the results obtained by measuring lead content in 9 samples of paint products according to the proposed scheme in the described methodology, one can make a confident conclusion about the absence of exceeding the maximum permissible lead content, considering the expected reduction of the standard to 0.009%. Conclusion. The usage of the proposed method will make it possible to successfully control the lead content in paintwork materials at levels that comply with international standards and, in the long term, ensure that the requirements of the Technical Regulation of the Eurasian Economic Union «on the Safety of Paint and Coating Materials» are met in terms of reducing the regulatory indicator to 0.009%.