When you first hear the term ultraviolet light, what comes to mind? The most common thought is geared towards the sun and being outside. Damage caused by the sun is typically in the form of burns, which can range from first degree to third degree. The short and simple means of protection being the implementation and proper utilization of sunscreen with a sun protection factor (SPF) of 30+. Beyond the utilization of sunscreen products, exposure should always be limited when possible. Consider changing the timeline of work to earlier hours, which tend to have a lower index for ultraviolet light. While sun rays are a huge factor in the construction field, we should also be aware of laser emitting equipment.

Understanding The Hazards

In terms of OSHA standards, there is limited information regarding ultraviolet light hazards and protective measures required for operations on a jobsite. Not having OSHA standards to reference is not an acceptable reason for putting employees at risk. OSHA does provide technical guidance regarding protecting employees from ultraviolet light with respect to laser hazards (OSHA Technical Manual (TED 1-0.15A, Section III - Chapter 6). Apart from OSHA, an international standard has been created for the categorizing of laser hazards. The manufacturer of the laser system first classifies the laser and then certifies that it meets all performance requirements of the Federal Laser Product Performance Standard (FLPPS). Four classes are based upon a scheme of graded risks that considers the damage that could be caused to skins cells or eyes based on watts[1]. Class (1) does not emit radiation at a known level of hazard. The most common example of this includes barcode scanners. Class (2) are low-power visible lasers. Laser tape measures or thermometers are very useful tools for specific operations.  Class (3) are moderate power lasers, which are essentially a step up from class two. Penetration under the skin can occur at this level and direct viewing can cause eye damage. Laser leveling devices are a common example of this class.  The final, which is Class (4), are high power lasers that should never be directed into eyes or even diffused through materials into eyes. These lasers are a potential fire hazard and significant control measures are required. Common examples include laser cutting machines.
 
Class Example  
1 Does not emit radiation at a known level of hazard Class 1
2 Low-power visible lasers Class 2
3 Moderate-power lasers Class 3
4 High-power lasers Class 4

Understanding Protection

Depending on the classification of the laser system, certain control measures should be implemented. In general, always review and follow equipment manufacture’s recommendations. Ensure training is understood by all associated with the task at hand. Ensure all safety measures and hazard labeling is present on the equipment. Anytime visible light is emitted, the source location and ending location must be communicated to all workers exposed. Upon the determination that laser equipment is needed, a pre-task analysis of hazards and control measures should be discussed with all workers associated with the operations. Communicating the hazard by means of highly visible and legible signage is strongly recommended. If a potential for diffusion at the end location is possible, ensure a material is utilized to absorb the light and not reflect it in other directions. Depending on the wattage, consider full screen protection in areas, or close access via danger tape for all unauthorized individuals. Limited duration for individuals should be the goal if exposure is necessary. Rotation of employees in affected areas is a common control method. The final level of protection to implement includes personal protective equipment.  ANSI Z136.1 rated, or equivalent, safety glasses or face shield should always be utilized to protect the eyes. Protective clothing such as long sleeves and gloves should be considered as well.

[1] Noun: the SI unit of power, equivalent to one joule per second, corresponding to the power in an electric circuit in which the potential difference is one volt and the current one ampere.

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