Brussels is on course to restrict the type of chemicals used in tattoo inks in response to an explosion in the popularity of body art and concerns that some of the substances used might cause cancer, change DNA or be harmful to human reproduction.

A proposal to implement tight limits on the use of 4,000 chemicals is expected to be brought to a vote among EU member states by the middle of next year, but the UK will not have a say as it is to leave in March.

The law would apply to the UK during the 21-month transition period, but it may not survive Brexit should Britain diverge from the EU acquis – the body of law made in Brussels.

Recent surveys suggest as many as one-third of 25- to 39-year-olds in the UK have tattoos.

The latest guidance from Public Health England says beyond a requirement that the inks used are sterile and do not react with the body, there are no common standards, despite evidence that some of the products are contaminated with potentially dangerous microorganisms and metals.

The European Chemicals Agency (ECHA) reported in October that it was “well known that tattoo inks can and do contain substances of concern such as identified carcinogens and skin sensitisers”. No direct link has been made between tattoos and the development of cancer.

EU member states backed a resolution in 2013 urging national governments to impose tight controls on the chemicals used by tattoo parlours, but the UK was not one of the seven countries to incorporate the guidelines into domestic law.

The proposed restrictions were discussed by ECHA committees in June and are due to be examined again in September before a formal opinion is sent to the European commission by the end of the year.

Mark Blainey, a senior scientific officer at the ECHA, said: “The commission then has three months to prepare a draft decision for the EU member states to vote on. This is likely to happen in mid-2019.

“If the council or the European parliament do not oppose the restriction, the commission adopts and publishes the restriction in the official journal as an amendment of the list of restrictions of the EU chemicals legislation, Reach.

“There is no harmonised process across Europe for assessing the safety of tattoo inks, although some member states have their own national legislation. So the European Chemicals Agency was tasked to assess the risks, the relevant socioeconomic impacts and the need for EU-wide restriction.

“The composition of some tattoo inks and permanent makeup raises concerns for public health. The most severe concerns are allergies caused by the substances in the inks and the fact that some of the substances might cause cancer, change DNA or be harmful to human reproduction.”

Tattoos involve the injection of ink into the second layer of skin, known as the dermis, where it remains permanently unless removed. Photograph: Alamy

The ECHA’s report found a particular link between red ink and dermatitis, due to the product’s high content of mercury sulphide. Red, blue, green and purple inks were said to be more likely to cause small ridges in the skin called granulomas.

Tattoos involve the injection of ink into the second layer of skin, known as the dermis, where it remains permanently unless removed using laser technology. As a result, the subject of the tattoo has long-term exposure to the chemicals injected, including the byproducts produced as they degrade. The pigments used by tattoo parlours, often imported from the US, are not specifically produced for use by tattoo artists.

In June, doctors writing in the medical journal BMJ Case Reports warned that those who have a tattoo and a weakened immune system risked complications. The report suggested patients, including organ donors, should be warned of the dangers.

The news site Politico reported that some tattoo parlours purchased inks from major chemical manufacturers despite those companies advising against their use in body art.

Gareth Thomas, a Labour MP and former minister, said he expected domestic legislation to keep in lockstep with the EU’s proposed regulations.

“It is difficult to believe the government aren’t committed to putting in place clear standards to stop the use of chemicals that could cause cancer in tattoo parlours up and down the country,” he said.

“With tattoo parlours in ever-increasing demand, British consumers shouldn’t have to rely on the EU to protect them – their own government ought to be able to protect them, too.”