People’s health is being put at risk by Brussels’ slow response to the use of dangerous chemicals, according to a report.

A study by ClientEarth, an environmental law organisation, found that in nine out of 10 cases the European commission’s decision to ban a toxic chemical after it had been identified was “excessively delayed”, sometimes for up to four years.

Alice Bernard, a ClientEarth lawyer, said: “Once the European Chemical Agency (ECHA) concludes that risks from specific chemicals are not acceptable, the commission has a duty to act quickly. Some decisions have been sitting on the desk of the commission for more than three years now, for no apparent reason.

“Every day lost through this inaction means more exposure to harmful chemicals, increasing the likelihood of notably cancer, impairment of fertility, as well as long-term catastrophic damage to our ecosystems.”

Under the current regulatory system, known as Reach (Registration, Evaluation, Authorisation and Restriction of Chemicals), the ECHA’s scientific committees are in charge of assessing the risks of chemicals.

The commission then decides whether companies should be granted authorisation to use substances known to be of “very high concern”.

In most cases, companies are free to use the chemicals in question while the commission’s decisions are pending, despite the agency’s concerns.

ClientEarth cited as one example the case of DEHP, a plastic-softening chemical found to readily leach from the plastic and to be a hormone-disrupting substance toxic for human reproduction. The scientific committees concluded in 2014 and 2015 that companies requesting authorisation for DEHP were using it without adequately controlling the risks.

By the start of this month the commission had not yet adopted a final decision on these cases, meaning companies remained free to continue using the chemical, ClientEarth said.

Apolline Roger, another of its lawyers, said: “It is strikingly apparent that the cases where the commission acted most quickly were the cases where the companies could not legally use the chemicals while waiting for the commission’s decision.

“It is particularly worrying to see that the commission prioritises business interests but not the protection of human health and the environment when deciding which cases are urgent.”

ClientEarth said it had written to the commission to share its findings and to call for it to “correct its maladministration and speed up the authorisation and restriction processes”.

A spokesman for the commission said it took human health extremely seriously and strongly rejected claims that it prioritised business interests over health and the environment.

A statement said that in the past 10 years the commission had “significantly reduced our citizens’ exposure to harmful chemicals. Overall, more than 17,000 substances in 65,000 registration dossiers of chemicals manufactured and used in the EU have been registered as part of the Reach registration procedure.”

The spokesman said the process was being constantly evaluated to “further enhance protection of consumers, workers and the environment”.