Posted: 3 Jul '17

Compliant Gas Monitoring: Understanding OSHA’s Exposure Requirements

OSHA Compliant Gas Monitoring

The Occupational Health & Safety Administration (OSHA) has standard requirements for air monitoring to make sure all employees are kept safe from noxious gasses in the workplace. Specific requirements apply to confined spaces. Understanding OSHA requirements for gas monitoring is the first step in creating a safe working environment. An effective gas monitoring system will help ensure that toxic gases do not harm your workforce.

Acceptable types of exposure monitoring

Where dangerous gases may be found, OSHA requires a range of monitoring. Before a confined space is entered, a remote sampling device must be used to check for adequate oxygen and dangerous concentrations of flammable and toxic gases. OSHA specifies that oxygen concentration must be measured first, then flammables, then toxics. That is because some flammables sensors don’t work in an oxygen deficient atmosphere. Where there is a high flammables concentration and low oxygen, ventilating will increase the explosion risk, and must be done with extra care.

At least one person in each group entering a confined space must wear a personal monitor which will alarm when it detects a hazardous atmosphere. Typically these monitors measure the concentration of Oxygen, Flammable gases and Hydrogen Sulphide and another toxic gas. The alarm level for each may be adjusted by a trained person. OSHA specifies a minimum oxygen concentration and a maximum for flammables. The OSHA regulations set “Action Levels” for many toxic gases. Where an “Action Level” is exceeded employers are required to take various actions. Safety personnel may select more protective alarm settings.

Ventilation is Key

Most confined space entries require ventilation before people go in and as long as they are in the space. The size and shape of the space, and known pollutant sources must be considered in selection of the ventilation system. IVS has the skills, equipment and experience to select and set up a ventilation system for any confined space. IVS technicians work closely with gas monitors to ensure that confined space atmospheres are safe before people enter, and stay safe until everyone is out.


People who may be required to enter a confined space must be informed of the effects of oxygen deficiency and toxic gases they may encounter. An evacuation plan and other safety measures must also be in place.

Innovative Ventilation Systems Can Help

For any inquiries about gas monitoring, and mechanical ventilation for your workplace, request a consultation online or call your local Innovative Ventilation Systems office to speak to one of our ventilation experts.