AIHA Releases IH Calculator App

AIHA recently released the free IH Calculator LITE app, a calculator that aids industrial hygienists in performing OH&S calculations quickly and efficiently on their mobile device. Topics include: Noise, Heat Stress, Ventilation, Exposure Assessment and is complimented with a range of conversions such as volume, distance, pressure, temperature, TLVs, and more. The app is […]

Calculator: Minimum Sample Volume & Required Sampling Time

Want to determine the Minimum Sample Volume needed to ensure you collect enough of a sample volume so that the results are capable of being less than the Exposure Limit? Want to know how long you need to sample at a given flow rate?

If so, use’s Minimum Sample Volume and Required Sampling […]

NTP (Normal Temperature & Pressure) Definitions

A few questions have arisen regarding the term NTP (Normal Temperature and Pressure). The following table helps to sort any potential confusion.

Agency Pressure Temperature Traditional

(Chemistry/Physics) 29.92 “Hg

760 mm Hg 492 ˚R

273 ˚K ACGIH


29.92 “Hg

760 mm Hg 530 ˚R


(Traditional) 29.92 “Hg


Worksheet: Analyzing Lifting Operations

Washington’s Department of Labor and Industries has created a worksheet based upon the NIOSH Lifting Equation to determine if a lift operation exceeds the recommended limits. A copy of this worksheet can be found here: (Worksheet: Lifting Limit Exceedance (881)). If you are unfamiliar with the NIOSH Lifting Equation, a good resource is […]


IHSTAT is a excel worksheet that enables statistical analyses of occupational hygiene measurement data and compliance testing (with occupational exposure limits). IHSTAT was developed by AIHA (American Industrial Hygiene Association).

Determines whether samples are normally distributed or log normally distributed. Where:

Normal distribution – data that clusters around a mean/average Log Normal distribution – […]

November 2009 CIH Exam Prep Questions

CIH Exam Prep Questions for November 2009 have been posted. 34 questions covering a range of Industrial Hygiene and Safety topics were put together by to test your knowledge. Any questions, please don’t hesitate to ask!

You can view the quiz HERE

When you complete the quiz, please put the number of questions […]

CIH Exam Preparation Questions Coming to

Monthly questions for individuals planning to take the Certified Industrial Hygiene examination will be posted on beginning November 1, 2009. Approximately 30-50 questions will be posted monthly and will cover the rubrics as defined by the American Board of Industrial Hygiene (ABIH).

Whether you are looking to sit for the exam, […]

Calculators: Injury and Illness Incidence Rate & DART

Want to calculate your Injury and Illness Incidence rate (I&I) and/or your Days, Away, Restrictions and Transfers (DART) rate? Use’s Incidence Rate and DART Rate calculator (Excel spreadsheet format) to determine your rates.

Download the Calculator HERE for use on your computer:Incidence Rate and DART Rate Calculator (6071)

Sample Screenshot IR & […]

Combined Toxic Effects of Chemicals

Below is a summary of some of the very similar methods and rationale used by agencies to assess the combined toxic effects of chemicals.

ACGIH Source: TLV’s and BEI’s Publication

Recommends an additive (combined) approach for two or more substances that affect the same target organ/system The ratio of the exposure concentrations are summed together […]

Adjusting Occupational Exposure Limits for Extended Work Shifts

OSHA currently has two standards in which the PEL is adjusted based on the length of the work shift, both of which are lead standards:

29 CFR 1910.1025 29 CFR 1926.62

All other PELs are based upon 8-hour time weighted average (TWA), a short term exposure limit (STEL), or a ceiling limit (C).

The […]