Ventilation Confined Space Entry Operation,

 

Ventilation is the best method for making a confined space atmosphere safe and free of hazardous air. Planning the confined space entry operation, and selecting the proper ventilation equipment is critical. It is almost an art form to ensure every nook and cranny of the confined space is continuously ventilated. It also takes a little math to figure out how long it takes to ventilate a certain sized confined space with the equipment you have.

Types of ventilation
Some confined spaces can be ventilated naturally. This is the case with most excavations. However, any time a naturally ventilated confined space is occupied, adequate precautions must be taken to prevent employee exposure to air containing less than 19.5 percent oxygen and other hazardous atmospheres.

Other confined spaces must be ventilated with mechanical equipment.

Ventilation is important to:
• Clear the confined space of hazardous air before you are permitted to enter.
• Keep the confined space clear of hazardous air while you are working in the space.
• Keep the confined space comfortable by lowering temperatures and providing fresh air.

Types of equipment
Blowers provide a continuous supply of outside air. Ventilation blowers can work two ways. They can either force fresh air into the confined space or suck the contaminated air out and pull fresh air in. The most popular (and efficient) method of the two is forced air.

Ducting is also important. The positioning can mean proper circulation and venting of the whole confined space or leaving pockets of contaminated air in corners.

If you are using blower equipment in a potentially explosive hazardous atmosphere you must use equipment designed to be spark-proof and have the ability to dissipate static electricity.

Because of the complications of selecting the right equipment, your site’s competent person must know how to evaluate the confined space and select equipment powerful enough to exchange air in the space. The size and configuration of the space and the output of the blower must be evaluated.

Confined space work can be safe. Proper and continuous ventilation is one of the best and easier methods to accomplish a hazard free confined space.

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