The phrase "a fatal amount of" is correct and usable in written English.
It can be used to describe a quantity of something that is lethal or deadly, often in contexts related to substances or conditions that can cause death.
Example: "The laboratory reported that the chemical spill contained a fatal amount of toxins, posing a serious risk to anyone nearby."
Alternatives: "a lethal dose of" or "a deadly quantity of".
She had slashed her wrists and also swallowed a fatal amount of antihistamines.
It was an upstate chicken, most likely, that had come to town just for the hell of it, but its life cycle — born elsewhere, arrived in hope, lived in cramped quarters, ended its New York existence violently and unexpectedly at the hands of someone with a fatal amount of money — seemed to make its life local enough to qualify.
Her injuries included a fractured skull and ruptured liver and she was found with a fatal amount of codeine in her system.
If you're not into that and basically can't be arsed, it would be prescient to take a fatal amount of alcohol with you, so you can get pissed and die quickly, just in case it all goes wrong and you have to watch your family being eaten by cannibals while trying to trade some old cigarettes for a bite of a Lion bar.
A Michelin star-winning protege of the celebrity chef Gordon Ramsay fell to his death from a window ledge after taking a potentially fatal amount of cocaine, an inquest heard yesterday.
It's a very dangerous combination of people not knowing what they're taking, and not knowing how much is a fatal amount or not.
Last month, an inquest in the West Midlands heard how Jason Nock, 41, bought AH-791 online and died after accidentally taking five times the fatal amount of it.
In fact, any strong emotional reaction can trigger fatal amounts of a chemical, such as adrenaline, in the body.
Police and medical examiners increasingly report opioid varieties laced with fatal amounts of fentanyl or carfentanil, a drug used to sedate elephants.
Toxic and even fatal amounts of phenol can be absorbed through relatively small areas of skin.
The inquest heard that as well as the heroin, toxic to fatal amounts of methamphetamine and traces of cannabis were found in her system.
