CYANIDE is one of the most famous and deadliest poisons known to man as it emerged insulation fitted to Grenfell Tower may have given off the highly toxic gas which lead to the deaths of at least 80 victims.
But the potentially lethal chemical does also have a number of legitimate uses. Here’s everything we know about cyanide.
Cyanide is a chemical compound consisting of carbon and nitrogen.
It can take many different forms, such as sodium cyanide, potassium cyanide or hydrogen cyanide, to name a few.
Many variants of the chemical are highly poisonous to humans, causing death within minutes.
The chemical’s deadliness is summed up by the fact that a number of leading Nazis used potassium cyanide suicide pills to kill themselves towards the end of the Second World War.
One of the most dangerous variants is hydrogen cyanide which takes the form of a gas at room temperature and can be inhaled.
Humans suffering from hydrogen cyanide poisoning can feel its effects within seconds of exposure to the deadly chemical.
Symptoms include weakness and confusion, headaches, nausea and difficulty breathing.
Sufferers can go on to pass out and suffer seizures before having a heart attack and dying.
There are cyanide antidotes which can be administered to render the poison harmless even after it is ingested.
But cyanide is so fast acting – having the potential to kill within minutes – that time is of the essence.
Cyanide has many uses. It is important in the mining of gold and silver, being used to dissolve the metals and their ores in order to refine them.
It is used in industrial chemistry, such as in the production of the material nylon, and has numerous medical uses.
The chemical is also used in pest control, being a key ingredient in the poison used to kill animals like rats.
And it has been used for illegal fishing and poaching around the world – with recorded incidents of poachers in Africa using it to poison water holes to kill elephants en masse for their ivory.
A variant of the chemical was also reportedly present in the insulation fitted to the outside of Grenfell Tower in London, which caught on fire killing scores of people.
An expert claimed the smoke from the burning material would have been filled with lethal hydrogen cyanide.
And the positioning of the insulation meant every flat could have been filled with enough gas to kill those inside, it was said.
At least one survivor of the blaze - 12-year-old Luana Gomes - was diagnosed with "cyanide poisoning" according to her medical discharge papers after she was unconscious for six days in hospital, the BBC has learned.
Her mum Andreia was unconscious for four days and sister Megan was kept in a coma for a week.
All three were treated for a cyanide antidote but Luana was only one who had been poisoned by the harmful chemical.
The BBC's environment correspondent Roger Harrabin said: "It sounds dramatic because cyanide is known is popular culture as the poisoner's weapon.
"But cyanides are also produced by some bacteria, fungi and algae."