This is a calculator for some of the equations found in the environment, health and safety (EHS) and industrial hygiene profession. There was originally an IHcalc app, aka IHcalc Lite. This was the product of some very smart students at Arizona State University. This is a new creation as an homage to that original app. This is version 1.0 of IHehsCALC, and I hope you will find it useful. The app is free, but we really, really, really, REALLY would like to see some folks make a donation to the American Industrial Hygiene Foundation. Also any corrections or suggestions please let us know via the help URL.