Video caption Trump made the comments about "heat and light" during a government briefing

A leading disinfectant producer has issued a strong warning not to use its products on the human body after Donald Trump suggested they could potentially be used to treat coronavirus.

Reckitt Benckiser said "under no circumstance" should its products be injected or ingested.

On Friday, Mr Trump said his comments during Thursday's coronavirus taskforce briefing had been made "sarcastically".

Disinfectants are hazardous substances and can be poisonous if ingested.

Even external exposure can be dangerous to the skin, eyes and respiratory system.

Mr Trump's comments have been heavily criticised by doctors and have generated a huge online response. They have provoked hundreds of thousands of comments and caused well-known cleaning brands to trend on social media.

Reckitt Benckiser, which owns brands including Lysol, Dettol, Vanish and Cillit Bang, said its products should not be administered "through injection, ingestion or any other route".

"Our disinfectant and hygiene products should only be used as intended and in line with usage guidelines. Please read the label and safety information," the company said in a statement .

What did President Trump say?

During Thursday's White House coronavirus task force briefing, an official presented the results of US government research that indicated coronavirus appeared to weaken faster when exposed to sunlight and heat.

The study also showed bleach could kill the virus in saliva or respiratory fluids within five minutes, and isopropyl alcohol could kill it even more quickly.

Mr Trump then hypothesised about the possibility of using a "tremendous ultraviolet" or "just very powerful light" on or even inside the body as a potential treatment.

"And then I see the disinfectant where it knocks it out in a minute. One minute," he said. "And is there a way we can do something like that, by injection inside or almost a cleaning?

"Because you see it gets in the lungs and does a tremendous number on them, so it'd be interesting to check that," he said.

Video caption Doctors dismantle Trump's treatment comments

In a statement on Friday morning, the White House press secretary said the president had "repeatedly" told Americans to consult doctors about coronavirus treatment.

"Leave it to the media to irresponsibly take President Trump out of context and run with negative headlines," Kayleigh McEnany said.

However, the White House statement did not make any reference to the comments being sarcasm.

On Friday afternoon, Mr Trump told journalists: "I was asking a question sarcastically to reporters like you just to see what would happen."

The president's comments have dominated social media platforms like Twitter and Reddit since Thursday night. Many compared his idea to a dangerous viral trend in 2018 where people ate Tide laundry detergent pods.

The Maryland governor's office said the state's emergency management agency issued an alert warning against injecting or ingesting disinfectants after receiving more than 100 calls to a hotline.

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Lysol, which is one of the America's best known cleaning brands, has been named in tweets at least 125,000 times since the White House news conference.

Owners Reckitt Benckiser said they issued their statement on Friday "due to recent speculation and social media activity".

What's the medical reaction been?

Doctors warned that the president's suggestion could have fatal results.

"These products have corrosive properties that melt or destroy the lining of our innards," McGill University thoracic surgeon Dr Jonathan Spicer told the BBC.

He said suggesting ingestion of a household cleaning product was "extremely dangerous".

"No one should be undergoing any preventative measures, as suggested by the president, without some kind of guidance from a licensed physician with the expertise in managing Covid-19," Dr Spicer added.

Meanwhile, Dr Donna Farber, an immunologist at Columbia University, told the BBC Mr Trump's suggestions of using ultraviolet (UV) light were "not practical".

"UV doesn't really penetrate very far," she said. "So even if you were to put it inside or outside, it's not going to even get to the lung... we just get a suntan or sunburn, and it causes DNA damage."

Dr Farber also said any radiation that would penetrate deeply enough " would cause so much damage that you're better off with coronavirus".

Image copyright Getty Images Image caption Mr Trump directed his seemingly off-the-cuff suggestions to Dr Deborah Birx, his coronavirus response co-ordinator

This is not the first time that Mr Trump's medical advice has generated controversy and criticism.

He has previously hyped a malaria medication, hydroxychloroquin, despite a lack of clinical evidence it helps treat Covid-19 and some concerns it can even be detrimental.

Poisoning and death risks

Analysis by Rachel Schraer, BBC health reporter

Using a disinfectant can kill viruses on surfaces. It's a very good idea to keep clean the things you touch, using products with anti-microbial properties - for example, substances with a high alcohol content.

There is also some evidence that, in general, viruses on surfaces die more quickly when directly exposed to sunlight. But we don't know how much or how long they have to be exposed for UV light to have an effect, so you're far safer just washing your hands and surfaces and trying not to touch your face.

Crucially, this is only about infected objects and surfaces - not about what happens once the virus is inside your body.

One of the main ways of catching the virus is by breathing in droplets expelled by an infected person, mainly by sneezing and coughing. The virus very quickly begins to multiply and spread, eventually reaching the lungs.

Not only does consuming or injecting disinfectant risk poisoning and death, it's not even likely to be effective.

Equally, by the time the virus has taken hold inside your body, no amount of UV light on your skin is going to make a difference.

And since UV radiation damages the skin, using it to kill the virus could be a case of - to borrow a well-worn phrase - the cure being worse than the disease.

Earlier this week, the US Centers for Disease Control and Prevention warned Americans to be careful with cleaning products as sales of household disinfectants soar amid the pandemic.

"Calls to poison centres increased sharply at the beginning of March 2020 for exposures to both cleaners and disinfectants," the agency's weekly morbidity and mortality report found .

The US Food and Drug Administration has also warned against ingesting disinfectants , citing the sale of bogus miracle cures that contain bleach and purport to treat everything from autism to Aids and hepatitis.

Last week, a federal judge secured a temporary injunction against one organisation, known as the Genesis II Church of Health and Healing, for marketing one of these products as a potential coronavirus cure.

Additional reporting by the BBC's Shrai Popat.