Using Compressed Gases Safely

 

Overview
Compressed gases are hazardous because of the high pressure at which they are stored in cylinders and pressure tanks. The compressed gases can be flammable, poisonous, corrosive, or any combination of these.

How can they hurt me?
Mishandling of compressed gases has been responsible for fatalities, serious injuries, and property damage that has amounted to millions of dollars. 

Flammable compressed gases:
• Explode if handled roughly or exposed to heat.
• Ignite by heat, sparks, or flames.
• Flash back if vapors travel to a source of ignition.
• Produce irritating or poisonous gas when burning.

Non-flammable compressed gases:
• Explode when in a mixture with fuels.

Health Effects of Compressed Gases 
Compressed gases:
• Are harmful if inhaled.
• Have extremely irritating vapors.
• Can cause cryogenic burns to skin and eyes.
• Produces irritating or poisonous gas when burning.
• Causes dizziness, unconsciousness, or suffocation.

Handling compressed gas cylinders
Compressed gas cylinders require careful handling to prevent damage. When handling cylinders:
• Move cylinders (securely fastened, in as near an upright position as possible) on special hand trucks.
• Don’t drop or bang cylinders together.
• Don’t roll, drag, or slide cylinders and never use cylinders as rollers or supports.
• Don’t lift cylinders by their caps.
• Don’t use magnets to lift cylinders.
• Cradles or platforms can be used to lift cylinders only if the cylinder was manufactured with lifting attachments.

Compressed Gas Storage
Some general guidelines in storing compressed gas cylinders include:
• Store cylinders in an upright position.
• Storing the cylinders in a safe, dry, well-ventilated place that is clean and free of combustible material.
• Avoiding areas where cylinders can be knocked down or damaged.
• Storing the cylinders in a position that ensures that the safety relief device is always in direct contact with the cylinder’s vapor space.
• Store oxygen CGCs at least 20 feet from flammables or combustibles, or separate them by a 5 foot, fire-resistant barrier.

Concrete and Masonry Construction

 

There have been a number of tragic accidents over the years involving concrete and masonry construction including one that happened during the time OSHA was preparing the current set of rules. In that accident a building in Bridgeport, Connecticut, collapsed, taking the lives of 28 workers. The collapse caused the highest death toll from a workplace accident in the United States since 51 employees were killed in 1978 during construction of a cooling tower at Willow Island, West Virginia. The Bridgeport building that collapsed was being erected using the lift-slab method of construction. OSHA's investigation of the collapse revealed that there had been a failure to comply with the OSHA regulations.

The OSHA regulations require your employer to train you in the recognition and avoidance of unsafe conditions and the regulations applicable to your work environment to control or eliminate any hazards or other exposure to illness or injury. That would include the hazards of concrete and masonry construction.

OSHA's standard for concrete and masonry construction is located in 29 CFR 1926, Subpart Q — Concrete and masonry construction. The Subpart addresses requirements construction employers must comply with to protect employees from accidents and injuries resulting from the:

·            Premature removal of formwork.

·            Failure to brace masonry walls

·            Failure to support precast panel.

·            Inadvertent operation of equipment.

·            Failure to guard reinforcing steel.

The regulation is divided into seven major groups. They are:

Scope, application and definitions— Prescribes performance‑oriented requirements to help protect all construction employees from hazards associated with concrete and masonry construction operations at construction, demolition, alteration, or repair jobsites.

General requirements— Discusses general work practice requirements related to construction loads, reinforcing steel, concrete buckets, working under loads, and personal protective equipment.

Requirements for equipment and tools—Addresses the hazards associated with equipment and tools used in concrete and masonry construction.

Requirements for cast-in-place concrete—Discusses formwork in general, shoring and reshoring, vertical slip forms, reinforcing steel, and removal of formwork.

Requirements for precast concrete— Directs employers to ensure precast concrete wall units, structural framing, and tilt-up wall panels be adequately supported to prevent overturning and to prevent collapse until permanent connections are completed.

Lift-slab operations—Contains specific requirements for lift-slab construction operations.

Masonry construction—Requires employers to establish a limited access zone whenever a masonry wall is being constructed.

OSHA believes that if the concrete and masonry construction regulations are complied with, deaths and injuries that have plagued companies will be reduced

Competent Person

 

Air Monitoring

 

Overview
Air monitoring is a critical part of any confined space work environment. A confined space is an enclosed space with limited access, such as a storage tank, manhole, tunnel, or ditches more than four feet deep. Air monitoring is required to evaluate the hazards of the space and verify that conditions for entry are acceptable and remain acceptable during entry.

When do you monitor the air?
OSHA says you must monitor the air after draining an open surface tank previously filled with hazardous materials, e.g., cleaning fluids. The air must be tested before a worker enters it. During excavation operations, you must test the air when a hazardous atmosphere exists or could reasonably be expected to exist.

Many construction site situations may pose a “confined space” hazard for which you must monitor the air.

You should: (1) evaluate confined space conditions before entry is authorized, and (2) as necessary to ensure they are acceptable during work.
You should monitor the air using the following guidelines:

• Test for oxygen first because most gas meters are oxygen dependent and will not provide reliable readings in oxygen deficient atmospheres.

• Test for flammable gases and vapors second because the threat of fire or explosion is both more immediate and life threatening (in most cases).

• Finally, test for toxic air contaminants.

Who monitors the air?
The person in charge must know the proper use and calibration of monitoring equipment, and supervise its use. Recently, the permit-required confined space rule was modified to permit employees entering the space to observe the initial monitoring of the space. Authorized entrants, those who will go in and do the work, must know how to use the testing and monitoring equipment.

Testing the air
You should use equipment that is sensitive and specific enough to identify and evaluate any hazardous atmosphere that may exist or arise, so that proper procedures can be developed and acceptable entry conditions be established. When monitoring the air, you should follow the instrument manufacturer’s instructions.

Confined spaces can be life threatening but can be rendered harmless by correct procedures. Air testing and monitoring is one of the tools by which we obtain information to render confined spaces safe to enter.

This information is provided by: MarshMcLennan Agency