The US Food and Drug Administration (FDA) has declared that bisphenol A, a chemical used in baby bottles and canned foods, poses no danger to consumers.

However, the safety chiefs admitted further research was necessary to understand the substance’s long-term effect on humans and said last week “"there are always uncertainties associated with safety decisions."

The FDA had already said bisphenol was safe but agreed to re-examine its stance after the National Toxicology Program raised some concerns about possible risks to infants.

Its finding that that the plastic hardening chemical, which is similar to the hormone estrogen, is safe echoes the conclusion of the European Food Safety Authority (EFSA) published last month.