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Disinfectants, cleaning agents may kill viruses but poisoning can happen, so don’t dismiss the harm they can do

SINGAPORE — Burns and pain in the mouth and throat, vomiting, breathing problems and, in severe cases, permanent disability or death. These are some consequences when disinfectants, which contain hazardous substances, are ingested.

Disinfectants, cleaning agents may kill viruses but poisoning can happen, so don’t dismiss the harm they can do

Cleaning solutions such as bleach, chemicals that unclog drains, toilet bowl cleaners, rust removers and oven cleaners are toxic and contain various alkaline and acidic compounds.

SINGAPORE — Burns and pain in the mouth and throat, vomiting, breathing problems and, in severe cases, permanent disability or death.

These are some consequences when disinfectants, which contain toxic substances, are ingested.

United States president Donald Trump sent shivers down the spines of medical professionals when he suggested recently that research be done on whether Covid-19 might be treated by injecting disinfectant into the human body.

He was slammed for his comments and later said that they were meant to be “sarcastic”. The international medical community did not take any chances and issued warnings to the public not to drink or inject disinfectants.

On hard surfaces and textiles, disinfectants such as bleach may be used to kill germs and viruses such as Sars-CoV-2, the coronavirus that causes the infectious respiratory disease Covid-19.

But on human tissue, their corrosive nature could wreak havoc and cause permanent damage to the skin and body, depending on the type of disinfectant used, the amount ingested and how soon treatment is administered.

Despite the well-known risks, there were news reports of increased calls to New York City’s poison control centre pertaining to exposure to Lysol — a brand name of cleaning and disinfecting products — bleach and other household cleaners following Mr Trump’s comment.

While Singapore doctors approached by TODAY said that they have not encountered incidents spurred by the US president’s remarks, poisoning cases involving household cleaning products such as bleach are not unheard of at emergency departments here.


Associate Professor R Ponampalam, senior consultant with the department of emergency medicine at Singapore General Hospital (SGH), said that toxic exposures could be the result of accidents, for example when products are stored or labelled inappropriately, or intentional poisoning due to stresses in life.

“Whether accidental or intentional, most of these cases could be prevented with appropriate control measures,” he said.

Every year, the accident and emergency department of Changi General Hospital (CGH) sees under 25 such cases involving accidental exposure and intentional self-harm.

Dr Abhay Kant, associate consultant at CGH’s Emergency Medicine division, said that patients are from all age groups including seniors.

Assoc Prof Ponampalam of SGH said that poisoning occurs when chemicals enter the body when they are ingested, inhaled, through the skin or via injections.

“In the case of household cleaning agents, it is usually via the oral route, or occasionally, through the skin as a result of spillage. The major toxic effect of these cleaning agents is its corrosive action which results in burns to the areas exposed,” he added.

Dr Abhay of CGH said that there are different types of disinfectants available in the market with varying contents and concentrations. Cleaning solutions such as bleach, chemicals that unclog drain, toilet bowl cleaners, rust removers and oven cleaners are toxic and contain various alkaline and acidic compounds, he added.

The effects of ingesting disinfectants may range from mild symptoms to severe internal organ damage, depending on the contents and concentration of the disinfectant.

Dr Abhay said that symptoms, which can kick in within a few minutes or most commonly under an hour of ingestion, may include a burning sensation around the mouth with pain of varying degrees in the oral cavity including the tongue and gums, as well as the chest and stomach.

“The person may also experience difficulties in breathing and hoarseness of voice. Some may have vomiting and diarrhoea as well.” 


Children are a vulnerable group in the household where poisoning typically occurs.

A study here published in 2018 in the Singapore Medical Journal found that about half (49.7 per cent) of the 1,208 cases of poisoning seen at KK Women’s and Children’s Hospital (KKH) from January 2009 to December 2013 needed hospital admission.

More than 40 per cent of the poisoning cases involved household liquids and products such as hand sanitisers and bleach.

Dr Kao Pao Tang, head and senior consultant with the children’s emergency unit at National University Hospital (NUH), said that poisoning involving household products are almost entirely unintentional for those under the age of 12.

“Almost all (household cleaning products) are either hypochlorite-based or ammonia-based and are extremely foul-smelling. Hence, no sensible child will attempt to drink it\.” 

He estimated that the unit at NUH sees up to one to two cases of ingestions of household cleaning products each week.

“Most are due to products left unattended and accessible to the child who takes a taste of it,” he said.

“They would have had their mouths rinsed out by the parents (before they were sent to the children’s emergency) and usually nothing needs to be done on our part.”

However, if significant amounts have been ingested, such as in the case of intentional harm, Dr Kao warned that significant burns could result in areas that come into contact with the cleaning agent, particularly the oral cavity and oesophagus.

“Such injuries tend to result in acute life-threatening events and often permanent disability,” he said, referring to possible damage to the oesophagus that could require long-term tube-feeding. 


As no two poisoning cases are the same, Assoc Prof Ponampalam of SGH said that management decisions can be complex and cases need to be assessed by an experienced physician or toxicologist.

Dr Abhay of CGH said that there is no single antidote that can reverse the effects in these types of poisonings. Treatment is based on various factors, for example, the type of compound ingested, the amount and concentration as well as the amount of time that has lapsed since the ingestion as well as the patient’s symptoms.

“Most patients improve with observation and symptomatic medications. Severe cases may require invasive measures, such as inserting a breathing tube due to a swelling of the airways, or performing an endoscopy and surgery for severe burns of the digestive tract,” he said.

That being the case, Dr Kao of NUH said that the majority of accidental household ingestions are “harmless” because most household products are often of low concentration.

For instance, household bleaches contain around 3 to 5 per cent of sodium hypochlorite. If a small amount has been accidentally ingested, there may be immediate burning in the mouth and throat but it rarely causes serious burns, he said.

He advised getting the child to spit or rinse out the liquid, and drinking milk or water. However, do not induce vomiting before seeking medical attention. A gastric lavage (stomach pumping) might be required if a large amount has been swallowed.

If the person who has ingested poisonous substance is unconscious, the HealthHub website done by the Ministry of Health and the Health Promotion Board advises waking the person up to get him to spit out the poison.

Wipe the substance from the mouth and place the person in the recovery position — on the side with a cushion behind the back, and with upper leg bent forward — while waiting for medical help.

Take care not to accidentally get the hazardous substance on the skin while doing this, as poison can also enter the body through the skin sometimes.


In the KKH study, the researchers found that almost all, or 95.4 per cent, of the poisoning cases occurred at home.

Emphasising the importance of child safety measures and precautions at home, Dr Kao said that adults should never store industrial-strength cleaning products not meant for household use at home.

Highlighting the dangers, he said that he once encountered a parent who took home highly concentrated industrial-strength alcohol for cleaning purposes.

“He put it in a soft drink bottle and left it in the kitchen. His son took a swig, thinking it was Sprite, before spitting it out. When you put things that should not belong in the home and there are children in the house, there’s where the danger lies,” he said. 

While household cleaning products are often of low concentration, the same cannot be said for industrial-strength products that are not meant for home use. When highly concentrated products are accidentally ingested, even a small dose can cause severe damage.

Avoid accidental poisoning at home with these tips by Dr Kao and HealthHub:

  • Do not store cleaning products and other substances meant for industrial use at home.

  • Keep all household cleaning products and poisonous substances out of reach of children, for example, in a high cabinet and locked up.

  • Never place household cleaning products in areas and containers where they do not belong, such as in soft-drink bottles.

  • Label poisonous substances with a skull or crossbones logo. Teach your child to recognise that containers bearing these labels contain poison, not food.

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