Compressed Gas Safety
Compressed Gas Cylinders Handling and Safety
The Occupational Safety and Health Administration (OSHA) outlines employer workplace safety and health compliance requirements contained within their numerous safety and health regulations. Among them are General Industry regulations, 29CFR 1910, and Construction regulations, 29CFR 1926. They are then broken down into subparts to address specific topics. For instance, Hazardous Waste Operations & Emergency Response (HAZWOPER) is not in itself a General Industry regulatory subpart, but rather a section contained within a subpart. And in this specific case, Subpart H- Hazardous Materials.
HAZWOPER tends to get the most attention within Subpart H, but there are several others of note, and for the purpose of this article, we will address the first section of Subpart H, 1910.101 Compressed Gases.
However, it becomes immediately clear by how short this section is that OSHA defers to the Department of Transportation (DOT) and industry consensus standards incorporated by reference, specifically:
- Inspections- Hazardous Materials Regulations of the Department of Transportation 49 CFR parts 171-179 and 14 CFR part 103 and Compressed Gas Association Pamphlets C-6-1968 and C-8-1962
- In-plant storage, handling and utilization- Compressed Gas Association Pamphlet P-1-1965
- Safety relief devices- Compressed Gas Association Pamphlets S-1.1-1963 and 1965 addenda and S-1.2-1963
The above publications can be purchased from the Compressed Gas Association.
The next four sections, however, do contain more details about specific compressed gases, including:
For Construction industry applications, most reference for compressed gases will be contained within Subpart J, Welding & Cutting, 1926.350 with additional reference to another industry consensus standard, the American National Standards Institute, ANSI Z49.1-1967, Safety in Welding and Cutting.
Along with manufacturer specifications and recommendations, employers should consult these regulations and standards for compliance guidance. Taken from them below are tips and techniques for inspection, storage, transport,and use of compressed gases, and should be included as part of further required employee training.
Inspection
- Make sure the cylinder is equipped with the correct regulator.
- Inspect the regulator and cylinder valves for grease, oil, dirt, and solvent. Never use grease or oil to lubricate regulators or cylinder valves because they can cause an explosion.
- The cylinder should be placed so that the valve handle at the top is easily accessible.
- When using toxic or irritating gas, the valve should only be opened while the cylinder is in a working fume hood.
- Only use wrenches or tools that are provided by the cylinder supplier to open or close a valve. Pliers should never be used to open a cylinder valve. Some regulators require washers; this should be checked before the regulator is fitted.
- Refer to Safety Data Sheets (SDSs) for the gas being used for information regarding use and toxicity.
- Fire extinguishing equipment should be readily available when combustible materials can be exposed to welding or cutting operations using compressed cylinder gases.
Storage
- Gas cylinders must be secured at all times to prevent tipping.
- Use appropriate material, such as chain, plastic coated wire cable, commercial straps, etc., to secure cylinders.
- Gas cylinders cannot be stored in public hallways or other unprotected areas.
- Cylinders must be segregated in hazard classes while in storage.
- Oxidizers (oxygen) must be separated from flammable gases, and empty cylinders must be isolated from filled cylinders. The proper storage for oxygen cylinders requires that a minimum of twenty feet is maintained between flammable gas cylinders and oxygen cylinders or the storage area be separated, at a minimum, by a firewall five feet high with a fire rating of thirty minutes.
Transport
- Never drag, slide or roll a cylinder. Use a cylinder cart or basket.
- Always have the protective cap covering the valve when transporting the cylinder.
- Never transport the cylinder with the regulator in place.
- Make sure the cylinder is secured to the cart before moving it.
- Do not drop cylinders or strike them against each other or against other surfaces violently.
- Do not use the valve cover to lift cylinders; they could be damaged and become unattached. If the cylinder is dropped on a hard surface, as it can cause an explosion.
Use
- Back off the pressure adjusting screw of the regulator to release spring force before opening the cylinder valve.
- Open the valve slowly and only with the proper regulator in place. Stand with the cylinder between yourself and the regulator (cylinder valve outlet facing away) when opening the cylinder valve.
- Acetylene or other flammable gas cylinder valves should not be opened more than 1⁄2 turns of the spindle, and preferably no more than 3⁄4 of a turn. This reduces the risk of explosion and allows for the cylinder valve to be closed quickly to cut off the gas flow.
- Never heat a cylinder to raise the pressure of the gas (this can defeat the safety mechanisms built in by the supplier).
- Keep the cylinder clear of all electrical circuits, flame, and sparks.
- Never leave the valve open when equipment is not in use, even when empty; air and moisture may diffuse through an open valve, causing contamination and corrosion within the cylinder.
- Do not refill a cylinder; mixing of residual gases in a confined area may cause a dangerous reaction.
- Never use copper fittings or tubing on acetylene tanks – an explosion may result.
- Never use compressed gas to dust off clothing, this could cause injury to the eyes or body and create a fire hazard. Clothing can become saturated and burst into flames if touched off by an ignition source such as a spark.
- Never leave pressure in a regulator when it is not in use.
- Valve protection caps should remain in place until ready to withdraw gas or connect to a manifold.
- Cylinder discharge lines should be equipped with approved check valves to prevent inadvertent contamination of cylinders connected to a closed system.
- Do not force connections that do not fit.
- Close the cylinder valve and release all pressure before removing the regulator from the cylinder.
- Do not smoke when oxygen or fuel gases are present, which could cause a fire or explosion.
To learn more about compressed gas safety, register for National Environmental Trainers' online course: Compressed Gas Cylinder Safety.
