Real-Time Protection for Workers in Construction & Fabrication Using Control Banding

Natural Ventilation

When dealing with chemicals of low hazard levels, construction and fabrication employers should implement natural ventilation and good industrial hygiene (IH) practices. Natural ventilation is the current state of control in many industries including welding construction, fabrication, and repair industries. This control approach ensures that workers should have unrestricted access to fresh air. In many situations, outdoor work would provide more ventilation. However, it may blow fumes into the beathing zone and compromise the weld. For workers who are confined to indoor environments, the continuous flow of clean air across the breathing zone is essential to reducing the concentration of airborne contaminants and potentially harmful substances.

Considering that construction and fabrication workers encounter several potential hazards on-the-job, it is recommended that employers make 5 air changes per hour to enhance air quality and keep workers safe. However, it is important to note that natural ventilation is not appropriate for carcinogenic welding fumes. 

In addition to these proactive measures, employers need to ensure that they have procedures in place to act promptly in the event of workplace accidents such as spills. Not only that, but employers should have well-established procedures to train workers on control measures, emphasizing the importance of using standard personal protective equipment (PPE) such as coveralls, safety glasses, and gloves.

Engineering Controls

Engineering controls such as Local Exhaust Ventilation (LEV) can reduce fume exposures if used correctly (that is, positioned 1 to 1.5 hood diameters from the arc) and routinely measured for effectiveness. LEV should be part of the solution but not the basis of a control approach. Even if LEV does not eliminate welding fumes at the source, it can enhance natural ventilation to reduce fume exposure to coworkers in the shop or in the immediate vicinity outdoors. 

If possible, it is recommended that employers enclose the source of danger to minimize harm. To maintain the effectiveness of LEV systems, annual testing is recommended to ensure that the ventilation systems continue to operate at optimal levels and safeguarding the health of construction and fabrication workers engaged in medium-risk tasks. 

Containment

Containment builds upon the previous control measures, emphasizing the importance of conducting material handling within closed systems with minimal breaches. Containment is necessary for welding exposures and chemical leaks. The containment needs to create a negative pressure at the source so that clean air moves into the contaminated zone. This scenario is ideal but may not be practical or available outside of dedicated, state-of-the-art manufacturing facilities.

Containment using PAPR

Most welding necessitates the worker being within arm’s length of the work, which makes an isolation room unrealistic; however, isolating the worker’s breathing zone is not. Use of a powered, air-purifying respirator (PAPR) is intended to create a containment level of protection for the welder during welding and thermal cutting processes. Because use of a PAPR is not true containment of the exposure, the control scheme must include protection for other workers, contractors, or visitors. Increased ventilation or LEV, restricted work areas, decontamination practices, and PPE should also be part of the control scheme. 

Expert Advice + Containment

When construction and fabrication workers deal with highly hazardous substances through extreme risk activities, multiple control strategies may be required to keep workers safe. To prevent instances of severe chemical damage and health risks, Exposure Control Plans (ECP) and preventative maintenance programs may be prescribed by health and safety consultants. For specific threats like lead, asbestos, and silica, health surveillance of construction and fabrication workers may need to be mandated. Often times, respirators will be assigned making medical fitness testing necessary.