Consumers have been warned to be careful when using commercial chemical products after nearly half of those recently checked have been declared as unsafe.

The European Environmental Bureau (EEB) has released details of tests conducted on 94 substances registered for use in Europe. It found that 49 per cent of these were not safe in their current state, due to their dangerous properties.

Chemicals policy manager for EEB Tatiana Santos said: “This is very concerning. Millions of tonnes of dangerous substances are being used unsafely in consumer and other products an getting into the environment.”

She went on to say companies often fail to provide enough safety information regarding their products, which is why it can take so long – more than a decade in some cases – for these perilous properties to be found out.

“Companies should face a much higher bar to market entry and also face losing market access if their data is found to be shaky,” Ms Santos suggested.

While the EEB determined protective action is required in all of the 46 cases, there has been no action regarding 74 per cent of these so far, mainly as a result of a lack of resources.

According to the organisation, these dangerous chemicals could have a significantly negative impact on human health, including fertility problems and increasing the risk of cancer.

While these 94 substances underwent high-quality checks last December, this is a marginal figure compared with the 22,000 products that are registered for use in Europe.

As Britain prepares to leave the European Union (EU), many UK chemical manufacturers – including those involved in toll processing – are uncertain what the impact will be on their businesses.

The Guardian recently reported that more than 50 companies have applied to move registrations away from Britain and use EU regulators so they can continue to conduct business without any interruption if and once Brexit takes place.