Industrial string lights are used to support temporary lighting systems. Such luminaries are commonly found in mining operations, warehouses and construction sites. The Occupational Safety and Health Administration (OSHA) and the Mine Safety and Health Administration (MSHA) governs the application of temporary string lights to ensure safety for operators and nearby workers in the site.
The need to oversee temporary lighting practices in hazardous work locations has increased in the past decade. According a report from the Department of Labor (DOL), work-related accidents in the mining sector increased from 36 in 2012 to 42 in 2013. Most of the accidents involved work surrounding heavy machinery and powered haulage equipment. Analysts have previously predicted that this rate will continue to increase prolifically in the coming years, due to the Obama Administration’s assertion to reduce funding for MSHA operations.
This article provides a general overview of specific OSHA and MSHA guidelines for industrial string lights.
OSHA Temporary Lighting Guidelines
String lights are non-permanent fixtures that are installed to illuminate various sections of the work site. In most cases, natural light from the sun must be supplemented with temporary lighting due to inadequate illumination (sunlight cannot penetrate through walls and large objects). During construction, such luminaries are typically installed after the building frame is completed. As other components are added to the building, such as pipes and ducts, the lights are blocked or covered from the completed section.
Illumination is top priority in hazardous work sites. OSHA Standard 29 CFR 1929.56 and 29 CFR 1926.56(a) suggests that general construction work must be supplemented with five foot-candles of lighting (minimum). For mining operations, a minimum of 10 foot-candles is required when drilling and inside tunnels. During installation, the temporary lights must be installed with ten feet of spacing in between each fixture. This is one of the toughest regulations to adhere to, because many buildings under construction have irregular floor plans. A solution to this issue involves utilizing shorter strings with several connected fixtures.
From a cost perspective, shorter strings are considered to be easier to remove upon completion of the project with an anticipated salvage rate of 75 percent. By comparison, longer strings are associated with more losses in the form of damages and failure due to destruction during the removal process (anticipated salvage rate of 60 percent).
OSHA String Light Recommendations
OSHA sets forth several recommendations for string lights in hazardous work locations. Below are some regulations that are often cited when manufacturing, installing and operating such luminaries:
• OSHA Lighting Requirements (1915.92): Temporary lighting (including string lights) must support guard mechanisms to prevent operators from accidentally contacting the light. Exceptions are provided for deeply recessed, inaccessible bulbs. Furthermore, it is recommended for cords to include adequate insulation.
• OSHA Standard 1926.405: This guideline focuses on hanging string lights by their cords. Such practices are only limited to cords and fixtures that are designed for suspension. Additionally, cords should be properly stored away from congested work areas.
• OSHA Standard 1915.82(b)(4): This ruling supports OSHA Standard 1926.405, suggesting that string lights should not be suspended using only the fixture’s electric cords. The exception to this guideline includes specially designed string lights that support and promote such practices.
• OSHA Standard 1915.82(b)(5): String lights should not overload branch circuits.
• National Electrical Code (NEC) Article 305: This regulation closely supports OSHA guidelines for temporary lighting. Specifically, the article dictates that temporary wiring at intervals should be in place for protection from unforeseen damage and to streamline the application of cable assemblies.
For lighting manufacturers that specialize in temporary string lights, design and production processes must adhere to the following guidelines: OSHA 1910 and OSHA 1926, UL Standard 1088 (temporary light strings) and NEC Article 305 (temporary wiring).
Individuals should carefully note that in locations where temporary lighting cannot be installed, employers are required to provide portable or emergency lighting options (OSHA 1915.82[c]). Furthermore, in hazardous work locations where volatile compounds are present, employers must install explosion proof lights approved for hazardous conditions through a Nationally Recognized Testing Laboratory (NRTL). Such fixtures must adhere to specific Classification, Division and Group ratings that match the ignitable elements in the hazardous work environment.
MSHA Temporary Lighting Regulations and String Lights
MSHA defines the use of light fixtures in Volume V “Coal Mines” (75.1719-2 Lighting Fixtures; Requirements). The section covers an extensive range of luminaries, including stationary light fixtures and machine-mounted light fixtures. The application of string lights is recommended in 77.207 Illumination, asserting that mining sites must support quality lighting conditions for safety. In particular, operators should address the luminary’s glare, beam direction and diffusion. Such recommendations are also applicable to locations where moving machines are present. The lighting options provided by this regulation includes the following: machine-mounted fixtures, portable luminaries and fixed lighting systems.
In a 2002 MSHA report titled “Better Lighting for Metal-Nonmetal In-Mine Preblast Operations” conducted by Thomas Lobb (physical scientist), Harry Verakis (supervisory general engineer) and Wayne Colby (electrical engineer), the governing agency clearly cites that illumination for underground metal-nonmetal mines is required and additional lighting must be used according to the operator’s discretion (Part 57, Subpart P- Illumination, Section 57.17010, Electric Lamps [Ref. 1]).
To ensure adequate lighting conditions, it is up to the mining operator to inspect the work area at least one time during each shift (30 CFR Part 57, Subpart Q-Safety Programs, Section 57.18002, Examination of Working Places [Ref. 1]). Lastly, the primary light source for guidance and illumination while conducting mining operations is a worker’s cap lamp (used to adhere to guidelines in 30 CFR Part 57.18002), and not temporary lighting systems.