Efforts by Brussels to dilute the bloc’s chemical laws are undermining the European Union’s credibility as a “global leader in green policy and the rule of law,” a top U.N. human rights official has warned in a letter shared with POLITICO.

“Simplicity and efficiency should not come at the expense of retrogressive measures or the health of the population, especially those that are the most vulnerable to toxics and pollution such as children,” writes U.N. Special Rapporteur on Toxics and Human Rights Marcos Orellana.

The source of Orellana’s concern is a European Commission proposal, published in the summer, to simplify a set of EU laws spanning cosmetics, fertilizer and chemical classification regulations in a “chemicals omnibus” bill.

The aim of the bill is to create a “more predictable and less burdensome regulatory landscape” — part of the EU’s broader simplification drive to help Europe’s businesses and boost its economy.

But the proposal “seems to conflict with [the] rights set out in the Charter of Fundamental Rights of the European Union, including the rights to health and environmental protection,” Orellana writes in his letter, dated Sept. 25 and addressed to the bloc’s delegation to the U.N.

The bill proposes, for example, that some of the rules governing what sort of cancer-causing chemicals are allowed in cosmetics be relaxed — angering consumer groups who warn it could endanger people’s health.

Orellana expresses misgivings about the “weakened safeguards preventing the use of [carcinogenic, mutagenic or reproductive toxic substances] in cosmetics,” and writes he is “particularly concerned” by new proposed flexibilities on product labeling and advertising. He notes the bill has not undergone a full impact assessment.

As it stands, he concludes, there is a “high risk” that the proposal would “negatively impact human rights, including the rights to health and a healthy environment, reversing recent improvements and creating legal uncertainty for businesses that have already invested in compliance.”

Moreover, he sees “no compelling justification to explain the abovementioned measures,” and asks “how the EU intends to ensure [the] compatibility of the proposed omnibus package with international human rights norms and standards.”

Industry groups including the European Chemical Industry Council and Cosmetics Europe have welcomed the bill, with the latter denying the legislative tweaks will impact consumer safety.

The file is currently being negotiated by the European Parliament and EU countries.