It should be noted that long before OSHA, and long before direct-reading instruments were available, people were doing toxic gas detection to protect their employees; combustible gas detection to protect their employees and their facilities; and, of course, they also did this to obtain lower insurance rates.
These days, though, you can count on government regulations being in place to either guide your every move—or at least make helpful suggestions. Although our remarks are confined to US government agencies or non-governmental organizations (NGOs), similar decrees and statutes exist in many other countries.
Even before concerning oneself with the regulatory maze, a thorough hazard assessment should be performed to determine the types of gases that are present, and under what conditions they could be released. It may turn out that a low background concentration of various substances is unavoidable.
In the realm of potential toxic gas exposures, as detailed in 29 CFR 1910.1450b, OSHA defines the action level as:
A concentration designated in 29 CFR part 1910 for a specific substance, calculated as an eight (8)-hour time-weighted average, which initiates certain required activities such as exposure monitoring and medical surveillance.
In the majority of cases, some sort of gas detection instrument—or system—will be the most appropriate way to comply with this regulation.
As to combustible gas situations, various regulations and guidelines apply:
- 29 CFR 1926.800 covers the aspects of combustible gases in underground construction
- 29 CFR 1910.146 covers permit-required confined spaces
- Instrument Society of America (ISA) ANSI/ISA-12.13.01-2003
- The National Fire Protection Association (NFPA) produces many documents in this field
A draft technical report from ISA (ISA-TR12.13.03), entitled Guide for Combustible Gas Detection as a Method of Protection, references several other documents and may be of interest.
We strongly recommend consulting with one or more gas detection instrument companies to nail down the details of your application. We would also recommend this page on how to get started.
Please contact us if we can be of further assistance.