Lead is a naturally occurring element that is commonly found within the environment. It is virtually impossible to eliminate from the raw materials from which ceramic bodies, glazes and colors are made. The presence of such lead is defined as an unintentional contaminant. Conversely, when an element such as lead is deliberately added to impart a function such as appearance and durability then this is defined as an intentional contaminant..
It is Portmeirion Group's policy to not intentionally add harmful elements within the production of ceramic homeware irrespective of the place of manufacture and to use unleaded materials. To facilitate this we have full visibility of the materials used in our supply chains and a stringent test program in place to ensure all new product launches and existing lines are routinely tested by independent, accredited test houses to ensure any potential risk to our customers is kept as minimal as possible.
There have been instances of lead poisoning from ceramic food contact articles for as long as records have been kept. The significance of leaded ceramic glazes was identified over 300 years ago in the late 18th Century through the separate works of H Ebell and W A Lampadius. These works identified that when lead glazes are fired correctly then no lead would leach from the material in the presence of a strong acid (acting as a food substitute) and that in addition, poorly fired glazes would leach lead as a result.
These works identified that the most likely cause for lead poisoning was a result of ingesting food and drink that had been contact with a poorly constructed leaded ceramic article. Over time, advances in technology have proven that during the firing process, any lead present within the glaze would become chemically bound and form part of the glass-like structure. If a glaze was not sufficiently fired then these chemical bonds would not be as strong which would then be the source of any detected lead (if present). It is feasible that there may be slightly weaker lead ions on the surface of a glaze which would have the potential to leach into food or drink substrates but these would be detected in a test method based on metal release such as ASTM C927 or AOAC 18th Ed. (2005) Section 973.32.
This is one of the main reasons that leachable lead is the globally recognised method of analysis. There are many other methods of analysis that will claim to measure lead. However, the metal release lead test methods recognised by the United States Food and Drug Administration and taken into law in Acts such as California Proposition 65 are considered to be the most representative for measuring the risk of exposure to the general public.
Portmeirion Group has always stood behind the quality and safety of our products. In addition to the comprehensive testing schedule in place, we routinely review metal release acceptance limits on the global market and adopt the most stringent limits to help reduce any risk of metal release to the absolute minimum. For example, 50 years ago Portmeirion worked to a release limit of 2pppm (Parts Per Million) based on European regulations whilst the US limit at the time was 7ppm. Since 1991, the limits set out in California Proposition 65 have been the most stringent and we have adhered to a limit of 0.1ppm. This limit is always under review and Portmeirion Group is actively maintaining the lowest possible release limit.