47
Toxic effect of hydrogen cyanide
The first clinical symptoms of hydrogen cyanide poi-
soning are vomiting and impaired consciousness.
The range of concentration from which critical effects
can be expected is known from the analysis of cases
of hydrogen cyanide poisoning. The toxic effect
depends primarily on the maximum blood concentra-
tion reached rather than on the total amount con-
sumed.
Timeline of levels of cyanide in the blood after the consumption of different foods containing the same amounts of
bound cyanide (mean values of 12 test subjects)
Hydrogen cyanide blood count after the consumption of foods containing cyanide
Cyanide concentration in blood ( M)
4
2
6
8
10
12
14
16
0 minutes
60 minutes
120 minutes
180 minutes
Persipan
Linseed
Bitter apricot kernels
Manioc
For the risk assessments of the specified foods, the study
results mean in concrete terms that in line with the existing
BfR recommendation, bitter apricot kernels should not be
consumed at all or only in a quantity of up to two seeds
per day. Before eating, large amounts of manioc should
be prepared using traditional methods such as soaking,
milling or drying in order to reduce the content of hydro-
gen cyanide. The consumption of linseed is safe, even in
the presence of high cyanide contents, as long as the cur-
rent recommended daily allowance of a maximum of 15 g
at a time is observed. Marzipan and persipan, the maxi-
mum hydrogen cyanide limit of which is limited to 50 mg
per kg food according to EU regulation, are safe in terms
of hydrogen cyanide, even when consumed in very large
quantities.
Food Safety
