Certification of NIST SRM 2569 Lead Paint Films for Children's Products

Abstract

SRM 2569 Lead Paint Films for Children's Products is a new Standard Reference Material (SRM) developed for use primarily with X‐ray fluorescence spectrometry (XRF) instrumentation. It consists of three paint coatings, with nominally 0, 90, and 300 mg/kg of Pb added, on polyester substrates. The levels of Pb are appropriate for use when validating test methods intended for testing product compliance with the Consumer Product Safety Improvement Act. The Pb mass fraction, mass Pb per unit area, paint density, and paint thickness are all characterized to make these materials useful to users of different XRF instrumentation. These parameters are consistent with one another and can be used to demonstrate mathematical conversions between units of mass fraction and mass per unit area. The assigned values for these parameters were obtained through direct determinations using instrumental methods and via calculations using measured values for paint ingredients, paint composition, and physical properties. The paints are highly homogeneous among units, although within units, some localized areas enriched in Pb can be observed using microbeam XRF instrumentation. For this reason, SRM 2569 is not recommended for use with measured areas smaller than 1 mm diameter. The development of SRM 2569 is a good case study for the use of multiple, interrelated parameters and test methods to demonstrate the comparability of values derived from a variety of measurement processes. Published 2012. This article is a US Government work and is in the public domain in the USA.