Background Reference Documents

Functional Requirements for IH/OEHS Systems provide basic and advanced requirements one may need in a computer database system to make informed exposure judgments. This database tool affords one the ability to incorporate both qualitative and quantitative assessments.

Volunteers developed product Exposure Modeling Toolbox with the AIHA and Product Stewardship Society. Those looking for introductory and comparative information regarding the selection, inputs, outputs, and differences between models explored by the team and found to be useful in assessing exposures to humans from products are for use by those looking for introductory and comparative information regarding the selection, inputs, outputs, and differences between models explored by the team. It should not be considered exhaustive, as many models were explored but found to be inaccessible to the general member (fee-based, other languages, etc.), or were unwieldy or could not be validated as functional. Members are encouraged to participate in the member societies and raise awareness of new or unreviewed models to the AIHA Exposure Assessment Strategies Committee for further consideration.

Flame Resistant Clothing (FRC) Assessment Tool: Beta Test

A subteam of the Protective Clothing and Equipment Committee has developed this tool to assist users in determining if Flame Resistant Clothing (FRC) is required in the work environment. At this time we are inviting the AIHA community to beta test this tool and provide feedback.

Instructions for review:

1. Download the FR assessment tool and save it to your PC.

2. Use the tool to gather information and perform assessments. Be sure to follow the instruction guide and review the limitations and scope of the assessment.

3. Send your feedback by 08/31/2021 to the FR Tool Development Team at

For additional information, see Synergist June/July 2021 issue and plan to attend AIHce Education Sessions:

  • 1076 - K7: Challenges and Solutions for Flame Resistant (FR) Clothing Hazard Assessment and Selection, Part 1; 8:00 AM-9:00 AM
  • 1092 - L7: Challenges and Solutions for Flame Resistant (FR) Clothing Hazard Assessment and Selection, Part 2; 9:15 AM-10:15 AM

IH/OEHS Apps & Tools

The following software tools provide the practicing industrial hygienist with quick and easy access to the information necessary to evaluate exposure profiles and determine if the exposures are acceptable, not acceptable or if more data is needed to determine acceptability. Like all software tools, the results depend on proper tool use and quality data inputs appropriate to the exposure scenario. Users are encouraged to gain expertise in specific tool use via a study of the appropriate references as listed and participation in appropriate professional development courses. A new tool (December 2020) is designed to assess oxygen deficiency risks from simple asphyxiant releases.

Legal Notice: The Apps and Tools on this page are made available to you for your own personal non-commercial use only. No part of the Apps and Tools may be used in any other manner without the express written permission of the American Industrial Hygiene Association. Furthermore, you may not create derivatives of the Apps and Tools or otherwise reverse-engineer, disassemble, or decompile the Apps and Tools or otherwise attempt to derive the source code of the Apps and Tools unless source code access is expressly permitted by the American Industrial Hygiene Association. The unauthorized use of these Apps and Tools is illegal and may result in civil or criminal penalties under the U.S. Copyright Act or other applicable copyright laws.

TOOLS For the Practicing Industrial Hygienist

These tools are all free and are regularly updated. Several are available in multiple languages.

STEP 1: Data Collection

IH/OEHS Exposure Scenario Tool (IHEST) guides the assessor by collecting general information about the workplace, specific scenarios, and agents(s), providing cues for measuring or estimating the important determinants of exposure as generation and ventilation rates. It also prompts the user to specify the type of engineering controls; this information is needed later when making initial judgments by applying the Qualitative Exposure Assessment Checklist (see below).

STEP 2: Basic Characterization

Basic Exposure Assessment and Sampling Spreadsheet is an Excel-based template for entering air and noise sampling data.

STEP 3: Preliminary/ Initial Exposure Assessment (Tier 1)

The Qualitative Exposure Assessment Checklist (The Checklist) requires only four readily available pieces of information: Occupational Exposure Limit (OEL); Vapor Pressure of the pure chemical (VP) when the agent is gas or vapor form; observed or reported workplace control measures (observed level of control) and required level of workplace control (required level of control). It can be applied in just a few minutes using readily available information and is significantly more accurate than subjective, intuitive judgments. The user is referred to Chapter 6 of A Strategy for Assessing and Managing Occupational Exposures, 4th edition, AIHA Press.

STEP 4: Refined Assessment (Tier 2)

  • IHMOD 2.0TM is an Excel-based mathematical modeling spreadsheet similar to the previous IH Mod. 1.0, which is now obsolete. IH Mod 2.0TM gives the user a choice between running the model in deterministic (point value parameters as was in IH Mod 1.0) or in Monte Carlo Simulation mode, with choices of distributions of parameter values right in MS Excel with no other software needed. An IHMOD 2.0 Support_File is also available. It includes useful information about IH Mod 2.0TM . A spreadsheet tab to estimate liquid spill pool generation rates via the Hummel-Fehrenbacher equation, units of measure conversion tool, examples of generation rate estimation, a “Bootstrap” procedure tool, a summary of approaches to estimate ALPHA for the exponentially decreasing emission rate models, and some links to other resources. Please note that the support file is evolving and will be updated periodically with new information. Check back here for updates.
  • IHSkinPermTM is an Excel application for estimating dermal absorption. Basic knowledge of Excel is all that is needed to operate IH SkinPermTM . IH SkinPermTM is a work product of the AIHA Exposure Assessment Strategies Committee (EASC) and the Dermal Project Team (DPT) in collaboration with Wil ten Berg, author of the original SkinPerm model. Although various parameters and data outputs have been explained or defined in IH SkinPerm through comments tagged on individual fields, users are encouraged to read Chapter 13 of the Mathematical Models for Estimating Occupational Exposure to Chemicals, 2nd edition, AIHA Press, 2009, C. Keil Editor. This is a useful reference for understanding the science and terminology associated with skin permeation. You can find the details and description of the mathematical model and workbook here.
  • OHDModTM is a Microsoft® Excel workbook for predicting the oxygen content trends in environments where inert gas releases may lead to asphyxiation risks. ODHMOD uses a Near Field-Far Field approach and estimates the oxygen concentration percent by volume and as mmHg partial pressure over time in the two zones. In addition to output graphs, the time required for reaching a target level is provided. Results can be compared to reference values for typical human body reactions due to Oxygen Deficiency Hazards and the need for mitigation measures. Examples guide input values for multiple industrial scenarios. ODHMOD has a user-friendly multilingual interface like several other AIHA tools (More info ... watch the PowerPoint file). This workbook is a product of collaboration between AIHA and Università Degli Studi di Brescia (Italy). You can find the details and description of the mathematical model and workbook here.

STEP 5: Refining/Validating the Exposure Assessment

IHSTATTM is an Excel application that calculates various exposure statistics, performs goodness of fit tests, and graphs exposure data. Multiple languages are available. The book “A Strategy for Assessing and Managing Occupational Exposures” is intended to accompany this tool. It provides critical detail on the use and interpretation of the various statistical outputs.

The links below will show you how to adjust the macros settings in your version of Excel if needed.