A 30-year-old Madrid woman has died of apparent intoxication after cleaning her kitchen for two hours using a product that contains ammonia.
The woman called 112, equivalent to America's 911 or Britain's 999, at 3pm on Monday saying she felt faint, according to the emergency services.
But by the time firefighters were dispatched, there was no answer at the door and they had to force entry. The woman was found on the floor of her kitchen suffering cardiac arrest.
Paramedics tried CPR for 30 minutes before declaring the woman dead.
'Everything points to intoxication from inhaling ammonia,' a spokesman for the Agency of Security and Emergencies of Madrid said.
Ammonia is commonly found in glass cleaners, oven cleaners and toilet bowl cleaners.
Exposure to high concentrations of the chemical can burn a person's eyes, nose, and throat. It can also lead to lung failure, heart failure and it can even overpower the brain's defenses, causing brain damage.
Death from exposure to household cleaning products is rare. Products made for everyday use at home are a diluted form of the chemical. Industrial products, meanwhile, have much higher concentration.
However, Dr Kelly Johnson-Arbor, a medical toxicologist at the National Poison Control Center, warns that all cleaning products are irritants, and anyone can suffer severe symptoms if they don't take a break.
'The problem is the symptoms are not always that bad, so people may keep cleaning, but that prolonged exposure will irritate the lungs,' Dr Johnson-Arbor explained.
'There are things you can do to minimize the effects, like opening a window, but often people are cleaning in places with not very good ventilation or small spaces like a bathroom, which makes it complicated.
'The best thing you can do is to use one agent at a time, take breaks, and make sure the space is ventilated where possible.'
Crucially, she warns, no one should ever mix ammonia products with bleach, a combination which can trigger the release of chlorine gas, which is highly toxic.
'Sometimes people use ammonia to clean their toilet bowl for a streak-free shine, but they get bleach in there to make it look even cleaner. That is very dangerous, no one should ever do it.'
Risk of poisoning is higher for people with underlying conditions, particularly asthma or emphysema, which could be exacerbated by the fumes.
Lastly, Dr Johnson-Arbor adds, organic alternatives may not give you much relief.
'The products that don't contain ammonia or bleach probably contain other chemicals to achieve the same effect, so that doesn't mean that it isn't toxic.'