Haber's rule
In
in the early 1900s.Rule
Haber's rule states that, for a given poisonous gas, , where is the concentration of the gas (mass per unit volume), is the amount of time necessary to breathe the gas to produce a given toxic effect, and is a constant, depending on both the gas and the effect. Thus, the rule states that doubling the concentration will halve the time, for example.
It makes
Haber's rule is an approximation, useful with certain inhaled poisons under certain conditions, and Haber himself acknowledged that it was not always applicable. If a substance is efficiently eliminated in the host, for example, then Haber's Law breaks down in the limit of t approaching the
, rewriting the equation as the integral ∫Cdt = constant for arbitrary varying C and elapsed time T. It is very convenient, however, because its relationship between and appears as a straight line in aIn 1940, statistician C. I. Bliss published a study of toxicity in insecticides in which he proposed more complex models, for example, expressing the relationship between and as two straight line segments in a
See also
- LD50
- Toxicology
- Chemical warfare
- Area under the curve
References
- .
- PMID 10963858.