Mixtures - LEL, LC, LD...

[Pipeline1972]

Hello,

How can one estimate the Lethal Concentration of a mixture, for example: 5% Diborane in Nitrogen (5%B2H6/N2)

For the explosive limits (LEL,...), I understand i need to use Le Chatelier's principle: reciprocal of the sum of the mole fraction / LEL proportion.

Can I use the same principle to calculate the lethal concentration (LC50)?

Thanks!

Process - Piping
ing - EiT

 

[bchoate]

Pipeline1972

Let's consider a definition of the LC50 and see if we can get a question that I perhaps can answer.
The LC50 is a measure of exposure by inhalation. It is specifically, "the concentration of a toxic material (vapors, dusts, or gases.) that will kill 50% of specific test animals in 4 hours when administered as a single exposure."
The medium, air, is not toxic. Only the test material is toxic. For environmental issues, the LC50 is sometimes used for toxics dissolve in water. The toxic agent has to be at some concentration (ppm, mg/cubic meter) to kill 50% of the test animals in the short term exposure window. That is unalterable. If the toxic agent is in some medium such as nitrogen, then there may be two toxic agents. Nitrogen is toxic by asphyxiation if it lowers the oxygen concentration below a known level.
Bill Choate

 

[cheute79]

The two values (LC and LEL) are totally unrelated. They function on different "principles". It is almost like asking about the fuel economy of an orange.