Paint manufacturers still putting consumers at risk in Mexico with sale of toxic lead paints

Over half of paints sold in Mexico contain unsafe levels of lead pigments, including carcinogenic lead chromate, according to an analysis of over 200 paints purchased in shops throughout the country. The researchers behind the work say this highlights that such products continue to put consumers at risk and are calling for a ban on the use of lead pigments in paints sold in Mexico.

Dyes and paints often contain lead compounds to speed up drying times, enhance colour and increase longevity. However, repeated exposure to such additives can cause health issues – such as brain damage and high blood pressure – primarily affecting children and workers who make or use products containing these pigments. Many countries – including the US, UK and EU – now limit the amount of lead in paints to 90ppm.

However, Mexico has no regulations on the amount of lead in paints and other coatings. Previous studies have looked at the lead content in legacy paints, but these did not assess the use of leaded pigments in on-the-shelf paints.

‘Our effort was a very large study looking at over 200 samples from the market in Mexico among various kinds of paints,’ says Perry Gottesfeld at the US environmental charity Occupational Knowledge International. He adds that these samples included paints for homes and businesses, road paints and metal primers produced by over 50 Mexican firms and five foreign paint producers.

The samples were tested at a US lab accredited for lead analysis by the Environmental Protection Agency.

‘More than half of the paints on the market (55%) [in Mexico] contained lead above 90 parts per million,’ explains Gottesfeld. The team also found that some paints had lead content levels that reached 290,000ppm (29% lead). Twelve paint samples labelled as ‘lead-free’ contained up to 120,000ppm.

Gottesfeld explains that of the paints that exceeded safe lead levels, around 90% also contained high levels of carcinogenic lead chromate (PbCrO₄). The EU banned this use of the chemical in 2019, and BASF began phasing out its production as early as 2012.

‘It’s important to note that there are substitutes for all of these lead additives in paints,’ says Gottesfeld. ‘Those who have reformulated – like AkzoNobel, the largest paint company based in Holland – have told us that it’s actually no more expensive to use [organic-based] alternatives.’

‘The alarming finding was that the largest paint company in the world, Sherwin-Williams, was also making and selling these products in Mexico,’ says Gottesfeld. Sherwin-Williams is based in the US but produces paints through a subsidiary in Mexico and sells these branded paints at authorised retail outlets in country, he adds. The other three US-based firms whose paints were tested came in at under 90ppm of lead.

Julie Young, a representative of Sherwin-Williams, tells Chemistry World that the company ‘does not use lead compounds, including lead chromate, in any of its current formulations for any product’. She adds that ‘this is true regardless of where in the world they are manufactured’.

Gottesfeld stresses that formulations are just the recipes and not the actual product. ‘If Sherwin[-Williams] was seriously concerned about our laboratory testing or about the [lead] content of their paints, they could have offered to test the paints that we retained or to test similar products in their stores,’ he told Chemistry World via email. ‘Neither of these things have happened despite repeated correspondence over many months.’

He points out that the paints made in the US by Sherwin-Williams that were on sale in Mexico did not have lead levels exceeding 90ppm. When Gottesfeld has investigated cases of lead paints on sale in other countries, paint producers told the team that pigments were ‘mislabelled or lacked labelling’. The manufacturers claimed that this resulted in lead entering their paints unwittingly, although he says he has no way of knowing whether this has happened in Mexico.

Gottesfeld explains that the Mexican health ministry recently proposed enforcing a maximum lead content in paints of 90ppm, which is in line with the standards used by other countries across the globe. ‘We’re hoping that this recent evidence further influences the [Mexican] government to act and to put out the final standard this year.’