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.

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.

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) (latest version: 15, 2014) 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) (latest version: 33, 2015) 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 (latest version: 2.010, October 2021) 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 (latest version: 1.07, October 2021) 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 (latest version: 2.4, October 2021) 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 (latest version: 1.02, December 2021) 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.
  • Dermal Risk Assessment Model (DRAM) (latest version: 1.00, February 2022) tool provides a systematic screening evaluation of the relative risks of dermal exposure to a material and may be especially useful for the purposes of prioritizing additional analysis for specific materials or scenarios. This MS Excel spreadsheet tool includes HELP screens for its deterministic (single value inputs) and Monte Carlo Simulation (distributions of input values). It runs only in MS Excel (with macro-enabled mode) but requires no other software.
    The tool uses information about the nature of the dermal toxicity and categorical choices for exposure factors such as dermal contact area, contact frequency, dermal retention time, dermal concentration/loading and dermal penetration potential. The factors are used in an algorithm to estimate the risk and plot it on risk grid. As such, an understanding the tool’s inputs as defined (including potential limitations) and resulting outputs can guide the user to decisions about controls or for more refined risk assessments. However, it is also important for the user to carefully read the available HELP screens, and to have an initial basic understanding of the definitions and inputs used and the potential complexities of the input selection process. When in doubt, an expert should be consulted regarding the selection of inputs and outcomes of the tool.
  • FR Assessment Tool. Understanding, evaluating, and selecting FR clothing can be a challenge for many Health and Safety (H&S) professionals. Lack of recognition of the need for FR clothing leaves many workers without proper protection. Yet requiring it where it is not needed can be expensive and may unnecessarily add to the employee heat load and employee complaints. Therefore, it is important to accurately assess a workplace to determine the need for FR clothing. This tool is a simple Excel spreadsheet that H&S professionals can use to help them assess a work area to more accurately make decisions about the need for FR clothing.

STEP 5: Refining/Validating the Exposure Assessment

IHDA-AIHA is a version of the IH Data Analyst program (www.easinc.co) designed for EHS students and professionals taking classes or professional development courses on the analysis and interpretation of occupational exposure measurements. The program calculates the standard descriptive and decision statistics recommended by the AIHA, and includes goodness-of-fit procedures and graphs, several methods for analyzing datasets containing non-detects, and Bayesian Decision Charts, which were designed to assist in the selection of the most appropriate AIHA exposure control category. Those using IHDA-AIHA for paid work on behalf of their client or employer are asked to show their appreciation to AIHA and the program's author by donating $100 USD to the American Industrial Hygiene Foundation scholarship program for each installed copy.

Expostats
is a free toolbox of web applications from the University of Montréal for the interpretation of industrial hygiene measurements using the lognormal distribution. Tool1, 2, and 3 from Expostats answer the following questions, respectively: is my similar exposure group overexposed? Is my similar exposure group homogenous? What factors are associated with exposure levels in my dataset? All calculations are performed using Bayesian statistics and results are presented in the intuitive probabilistic form. An offline version is also available. Expostats is presented in an article from the Annals of Work Exposure and Health which was awarded the 2021 Bedford prize.

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.