Welding Fumes and Gasses Safety Unit Lesson 3

Welding Fumes and Gasses The gasses, fumes and dust produced by welding and cutting processes can be hazardous. There are 3 basic methods to protect personnel against hazardous fumes and gasses. Natural Ventilation- The movement of air through the work place caused by natural forces. Mechanical Ventilation- Portable or fixed fans that can be used to provide the necessary ventilation. Source Extraction- Uses a mechanical device that captures the welding fumes at or near the source of the arc.

Welding Fumes and Gasses Regardless of the ventilation system used, it is important to avoid breathing the welding fumes. Keep your head up and away from the fume plume, the term used to describe the fumes, gasses and particles created by the welding process. Observe the column of smoke and position yourself to avoid it.

Welding Fumes and Gasses Some welding consumables and base metals contain toxic materials that can require special ventilation. Materials such as: Barium Manganese Cadmium Nickel Chromium Silica Cobalt Zink Copper And some coatings like paint, chrome, galvanizing, or anodizing can also release toxic fumes when welded.

Natural Ventilation In many cases, natural ventilation provides the required level of protection. Some of the guidelines to determine if the natural ventilation is adequate are. The welding area must contain at least 10,000 cubic feet of air per welder. This represents and area of 22’ x 22’ x 22’ for each welder. The ceiling height must be no less than 16 feet. The area must not be designated as a confined space.

Source Extraction Source extraction, also called local exhaust, can be provided by portable, mobile, or stationary systems. The exhaust hood should be kept 4 to 6 inches from the source of the fumes, or as close as practical without interfering with the work.

Respirators Some special materials or job sites will require the use respirators to provide welders additional protection from harmful fumes. Respirators are grouped into 3 main types based on how they protect the wearer from the contaminants. Air-purifying respirators Supplied-air respirators (SARs) Self-contained breathing apparatus (SCBA) The selection of a respirator is based on the contaminants and its concentration levels.

Air-Purifying Respirators Air-purifying respirators provide the lowest level of protection. Made for use in areas that have enough oxygen to sustain life. Air-purifying respirators use special filters and cartridges to remove particles, gasses and vapors from the air. When the wearer detects any taste or smell, the charcoal cartridge can no longer remove the contamination and should be replaced. There are 4 common types of air-purifying respirators. No maintenance Reusable Low maintenance Powered air-purifying (PAPRs)

Supplied-Air Respirators Supplied-air respirators provide a supply of air for extended periods of time. Air is delivered through a high pressure hose that is connected to an external air supply. Some supplied air systems can be used in atmospheres that are immediately dangerous to life and health (IDLH).

Self-Contained Breathing Apparatus SCBAs can be used in oxygen deficient atmospheres, in poorly ventilated or confined spaces, and in IDLH conditions. These respirators provide a supply of air for 30 -60 min from a cylinder of compressed air usually worn on the users back.

Respiratory Safety Local and OSHA procedures must be followed for the selection and use of the proper respirator for the job. When respirators are used OSHA regulations require that employers have a respirator protection program consisting of. Employee training. Cleaning and disinfecting Sanitary storage Inspection Fit testing Pulmonary function testing The employer is responsible for providing the training and equipment. It’s the employee’s responsibility to use it!