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CH3041
ON-LINE LECTURE 23
BANDED TOXICITIES
• Comparative
toxicites are now more often
based on bands rather than discrete LD50
comparisons and the EEC classification
uses a set of fixed dose tests.
based on bands rather than discrete LD50
comparisons and the EEC classification
uses a set of fixed dose tests.
• The typical fixed
dose test bands are:
Band range Test value Label
< 25 mg/kg 5 mg/kg Very toxic
25 - 200 mg/kg 50 mg/kg toxic
200 - 2000 mg/kg 500 mg/kg harmful
> 2000 mg/kg 2000mg/kg “safe”
Band range Test value Label
< 25 mg/kg 5 mg/kg Very toxic
25 - 200 mg/kg 50 mg/kg toxic
200 - 2000 mg/kg 500 mg/kg harmful
> 2000 mg/kg 2000mg/kg “safe”
• Tests focus on toxic signs rather than mortality and take 14 days on rats typically. Human sensitivity
= rat value x 10
• Environmental limits called trigger
values are based on adverse biological effects. eg. H2O human drinks 1.5L/d ®dose
values are based on adverse biological effects. eg. H2O human drinks 1.5L/d ®dose
