May be derived from waste animal or vegetable matter. Used
in the preservation of meat products, such as, cured meats,
bacon, ham, tongue, sausages, smoked frankfurters, pressed and
tinned meats such as corned beef and some Dutch cheeses.
Potassium nitrate is probably better known for its use in gun
powder and fireworks or as a fertiliser for intensive crops
such as tomatoes and potatoes. As a food preservative it is
one of the most effective (and oldest) ways of preserving meat,
in particular inhibiting the growth of the bacterium responsible
Whilst in general it is rapidly excreted, under some specific
conditions it may be converted in the stomach and saliva to
potassium nitrite, which can prevent haemoglobin in the red
blood corpuscles performing as an oxygen carrier. This can lead
to cyanosis, sometimes called 'blue baby syndrome' in infants.
May provoke hyperactivity and other adverse reactions. Potentially
carcinogenic. Restricted in many countries. Also see E249.
In addition, prolonged exposure to even small quantities may
cause anaemia or kidney inflammation, with ingestion of large
amounts possibly causing severe abdominal pain and vomiting,
muscular weakness, vertigo and irregular pulse.
Not recommended for consumption by children.