Need a good reference text to help your understanding of the ABIH industrial hygiene formulas? Check out Industrial-Occupational Hygiene Calculations: A Professional Reference Second Edition. The most commonly used formulas are presented with explanations of each of the variables and an example of the formula in use, with the benefit of using units of measurement and shorthand for variables that are consistent with common industry practice. On the plus side, if you pick up the spiral-bound copy of the book on Amazon, you save a ton compared to the hardcover. The spiral-bound version is much more convenient to work with anyways. Have you found benefit to the book or found something better? Let us know in the comments below.