The powder is 30 times hotter than the hottest pepper

The powder is so hot that Blair Lazar's customers have to sign a legal waiver before tasting it.

When Mr Lazar himself tried his "16 Million Reserve" he says his tongue swelled up and hurt for several days.

The pure capsaicin, 30 times hotter than the hottest pepper and 8,000 times hotter than Tabasco sauce, is distilled from several tons of fresh peppers.

Mr Lazar describes the powder, produced in a laboratory by workers wearing sealed suits and masks to avoid inhaling the dust, as "pure heat".

The final product is a white, crystalline powder.

Capsaicin does not actually burn, instead it stimulates nerve endings in your mouth, giving the sensation of burning.

Over the past decade or so, manufacturers have taken the humble chilli pepper and distilled it into ever more fiery sauces.

The names of the concoctions - After Death Sauce and Insanity Sauce are just two - give some idea of the pain that is involved during and after consuming them.

The spiciness of the sauces is measured in what are known as Scoville Units.

The higher the number of units, the bigger the burn, although some manufacturers say that beyond about 350,000 units, the measurement becomes meaningless.