Category is based on the A/D value, which is determined by
dividing the total activity (A) of radiological material by the
D-value given in the table below.
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Category (A/D values)
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Definition
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1. Personally extremely dangerous
A/D >
1000
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likely to cause permanent injury to a person who handled it, or
were otherwise in contact with it, for more than a few minutes. It
would probably be fatal to be close to this amount of unshielded
material for a period of a few minutes to an hour.
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|
2. Personally very dangerous
1000 > A/D > 10
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could cause permanent injury to a person who handled it, or were
otherwise in contact with it, for a short time (minutes to hours).
It could possibly be fatal to be close to this amount of unshielded
radioactive material for a period of hours to days.
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|
3. Personally dangerous
10 > A/D > 1
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could cause permanent injury to a person who handled it, or were
otherwise in contact with it, for some hours. It could possibly -
although it is unlikely - be fatal to be close to this amount of
unshielded radioactive material for a period of days to weeks.
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|
4. Unlikely to be dangerous
1 > A/D >
0.01
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could possibly - although it is unlikely - temporarily injure
someone who handled it or were otherwise in contact with it, or who
were close to it for a period of many weeks.
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5. Not dangerous
0.01 > A/D
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No one could be permanently injured by this amount of
radioactive material.
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