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Britons are being exposed to a "cocktail of chemicals" from birth in our own homes, with MPs raising particular concerns about the flame-retardant chemicals used in home furnishings. What are the risks?

What are flame retardants?

Your living room sofa will almost certainly be covered in a flame retardant.

These chemicals help to prevent ignition from stray cigarettes or neglected candles and slow the spread of fire.

The most common flame retardants work by interfering with the chemistry of burning.

But that also means that the smoke that is produced can be more toxic - with the volumes of carbon monoxide and hydrogen cyanide, in particular, being increased.

Both gases are poisonous and, in many fires, inhalation of either gas proves to be a more deadly killer than the flames themselves.

Where are they used?

On foam, carpets and curtains. In paints, clothes, food packaging, home insulation, toys, electronic goods and car seats.

What are the risks?

Some flame retardants, including the most commonly used - aluminium hydroxide - are generally considered to be safe.

Those causing the most concern are brominated flame retardants.

These chemicals are persistent in the environment and tests have detected their presence in air, dust, soil, water, food and wildlife.

Humans then become exposed to the chemicals, mainly by breathing contaminated dust and from our diet, including oily fish and meat. Once in the body, they can stay there for several years.

Many types of flame retardants within this class now have restricted use or are banned altogether.

Some are being replaced with other chemicals, such as those using chlorines.

In 2017, chief medical officer Sally Davies said there was no known "causative linkage" between exposure from the environment and adverse health outcomes, but said phasing them out should be encouraged.

She added that the concern for human health was long-term interference with the thyroid hormone system because of some structural similarity between the chemicals and thyroid hormones.

Breast Cancer UK said some banned flame retardants can cause cancer while others still in use interfered with hormones, including oestrogen, thereby potentially increasing the risk of breast cancer.

What's the law?

Since 1988, furniture manufacturers have been required by law to use flame retardants.

The UK, unlike with most other product safety legislation, has its own laws on this and they are widely considered to be the strictest in Europe.

Advocates of the 1988 Furniture and Furnishings (Fire Safety) Regulations point to research from 2009 which found that the reduction in the rate and lethal nature of furniture fires equated to saving about 54 lives a year.

But some fear the regulations need updating as a body of evidence over the risks of certain flame retardants grows.

For policy-makers, there are competing risks. On the one hand, they need to make sure that sofas are as fire-safe as possible.

And on the other, they want as few flame retardant chemicals as possible - they are nasty chemicals and can actually make fires more lethal.

What about second-hand furniture?

Only furniture made before 1950 is excluded from the 1988 regulations.

What needs to change?

Image copyright Getty Images Image caption Two years on, residents report the emergence of the "Grenfell cough"

The Commons Environmental Audit Committee, made up of a group of cross-party MPs, has come up with a long list of recommendations for the government.

It wants to see a biomonitoring programme to find out levels of chemical exposure among people in the UK.

This would include a specific one for Grenfell residents and firefighters to detect the effects of exposure to the smoke from the devastating fire in west London in June 2017, which killed 72 people.

Residents have reported the emergence of the "Grenfell cough" and health problems including vomiting, coughing up blood, skin complaints and breathing difficulties, the committee said.

Other recommendations from the committee include:

reducing the use of chemical flame retardants in domestic furniture

changing the labelling system to spell out which chemicals are in consumer products. Currently many labels carry the words "Carelessness causes fire" but have no mention of the retardant used

removing children's products, including mattresses and buggies, from the scope of the Furniture and Furnishings Regulations, without delay

Chief medical officer Sally Davies, in her 2017 report, called for other materials and manufacturing techniques to be explored to find a natural flame-resistant alternative.

What does the government say?

A spokesman said the UK's furniture safety requirements were the highest in Europe.

"We are committed to improving environmental outcomes and reducing toxicity but need to do so in a clear, well-evidenced way which also improves fire safety," he said.

The Environmental Audit Committee is pressing the government to respond to a three-year-old review of furniture fire safety regulations by the Department for Business.

The government said it would respond before 25 July.