OSHAs electrical standards

The OSHA electrical standard requires your employer to provide either (1) GFCIs for receptacle outlets in use and not part of the permanent wiring of the structure or (2) an assured equipment grounding conductor program covering all cord sets, receptacles that are not part of the permanent wiring of the structiore, and equipment connected by cord and plug that are for use by employees. 

Will the electrical system meet OSHA/NEC standards ... 

OSHA now considers the NEC or NFPA/ANSI 70 as a national consensus standard. Article 517 of NFPA 70 contains special electrical requirements for healthcare facilities. Refer to 29 CFR 1926.401-449 for OSHA construction-related electrical requirements. In addition, state and local regulations may apply. Electricians and maintenance personnel must understand the OSHA electrical safety standards published in 29 CFR 1910.301-399. Electrical installations and utilization... 

OSHA s electrical standards address the government s concern that electricity has long been recognized as a serious workplace hazard. Beyond bums and cuts, anployees are subject to such dangers as electric shock, electrocution, fires, and explosions. The objective of these standards is to minimize such potential hazards by specifying design characteristics of safety approaches and designs in the use of electrical equipment and systems. 

OSHA s general industry electrical standards found in Subpart S 1910.301 through 1910.399, are based on the National Fire Protection Association s Standard NFPA 70E, Electrical Safety Requirements for Employee Workplaces, and the National Electrical Code (NEC). In addition to general industry, they apply to shipyard employment, longshoring, and marine terminals. 

OSHA considers 50 volts to be the recognized threshold for hazardous electric shock. Several OSHA and national consensus standards recognize this 50-volt threshold. OSHA s general industry and construction electrical standards both require guarding of live parts energized at 50 or more volts. Also, the NFPA70E and the National Electrical Safety Code have electrical safety requirements starting at 50 volts. 

OSHA now considers the National Electrical Code (NEC) or National Fire Protection Association (NFPA)/ANSI 70 as a national consensus standard. Article 517 of NFPA 70 contains special electrical requirements for healthcare facilities. Refer to 29 CFR 1926.401-449 for OSHA construction-related electrical requirements. In addition, state and local regulations may apply. Electricians and maintenance personnel must understand OSHA electrical safety standards published in 29 CER 1910.301-399. NEPA/ANSI 70 applies to every replacement, installation, or utilization of electrical equipment. Supervisors must inspect work areas for possible electrical hazards. Electrical current travels through electrical conductors its pressure is measured in volts. Resistance to the flow of electricity is measured using ohms, which can vary widely. Resistance determination considers the nature of the substance itself, the length and area of the substance, and the temperature of the substance. Some materials, like metal, offer very little resistance and become conductors very easily. Other substances, such as porcelain and dry wood, offer high... 

Whenever there is a chance of foot injuries due to impact, falling, or rolling hazards, objects piercing the sole, or electrical hazards, approved safety footwear is required. This broad requirement was a part of the 1994 OSHA PPE standard 1910.136. Management is required to make a hazard assessment of the workplace to make a determination as to what PPE is required. The forms needed to make these assessments are at the end of this chapter. All protective footwear must conq)ly with ANSI Z41.1 1991 American Standard for Personal Protection -Protective Footwear. The standard steel toe shoe or boot must be chosen to fit the tasks, hazards, and environment in which they will be worn. 

Electrical safety violations are frequently a part of OSHA inspections. Violations of the electrical standard can be grouped into three key areas ... 

Health and Safety Factors. Sulfur hexafluoride is a nonflammable, relatively unreactive gas that has been described as physiologically inert (54). The current OSHA standard maximum allowable concentration for human exposure in air is 6000 mg/m (1000 ppm) TWA (55). The Underwriters Laboratories classification is Toxicity Group VI. It should be noted, however, that breakdown products of SF, produced by electrical decomposition of the gas, are toxic. If SF is exposed to electrical arcing, provision should be made to absorb the toxic components by passing the gas over activated alumina, soda-lime, or molecular sieves (qv) (56). 

Toxicity. Sulfur tetrafluoride has an inhalation toxicity comparable to phosgene. The current OSHA standard maximum allowable concentration for human exposure in air is 0.4 mg/m (TWA) (54). On exposure to moisture, eg, on the surface of skin, sulfur tetrafluoride Hberates hydrofluoric acid and care must be taken to avoid bums. One case of accidental exposure of electrical workers to decomposed SF gas containing SF has been cited (108). 

Entry into Confined Spaces. In 1993 OSHA adopted a confined space entry rule (93) requiring employers to evaluate the workplace to (/) determine if it contains any confined spaces, (2) mark or identify such confined spaces, and (2) develop and implement a permit program for entry into such spaces. The program must include a permit system which specifies the steps to be taken to identify, evaluate, control, and monitor possible electrical, mechanical, and chemical ha2ards select and use equipment institute stand-by attendance and estabflsh communications. The reference standard (93) should be studied for details. 

Hot Work. The objective of a hot work standard is to prevent fires, explosions, and other causes of injury which might result from workplace ignition sources such as welding (qv), cutting, grinding, and use of electrically powered tools. The OSHA standards have specific requirements (36,94) for fire prevention and protection and a permit system. 

Interior wiring design and installation for most commercial and industrial uses should follow the National Electrical Code (NEC) which has been a national standard since 1970 with the passage of the Occupational Safety and Health Act (OSHA). Some localities, however, may not accept the NEC and require that their own (more stringent) standards be followed. 

The National Fire Protection Association classifies liquids by their explosion and flame-propagation abilities.16,17 These ratings are then used to specify the type of electrical equipment required. These standards have been adopted by OSHA. Woinsky18 gives a procedure for obtaining the material classifications of individual compounds and mixtures. 

In its NEP, OSHA points out that for workplaces not covered by 1910.272, but where combustible dust hazards exist within dust control systems or other containers, citations under section 5(a)(1) of the OSH Act (the General Duty Clause) may generally be issued for deflagration (fire) or explosion hazards. National Fire Protection Association (NFPA) standards should be consulted to obtain evidence of hazard recognition and feasible abatement methods. Other standards are applicable to the combustible dust hazard. For example, if the workplace has a Class II location, then citations under 29 CFR 1910.307 may be issued to those employers having electrical equipment not meeting the standard s requirements. 

Much of OSHA s early work centered around abating mechanical and electrical hazards in the workplace. Beginning with the Hazard Communication Standard in 1986, however, a larger emphasis was placed on eliminating chronic hazards associated with workers exposure to chemicals, including colorants. 

Other standards in the safety area that are most often citied by OSHA and which must be considered in detailed designs are the. National Electric Code and Machinery and Machinery Guarding. A cursory investigation by a designer of these and other OSHA standards quickly points out several problems, particularly in interpretation. The standards frequently do not allow for alternate... 

Light Microscopic Method. Phase contrast microscopy (PCM) accurately assesses fiber exposure levels for fibers 5 pm in length and >0.25 pm in diameter. Furthermore, PCM cannot differentiate between asbestos and nonasbestos fibers. Currently, the standard method for the determination of airborne asbestos particles in the workplace is NIOSH Method 7400, Asbestos by Phase Contrast Microscopy (NIOSH 1994a). OSHA considers that sampling and analytical procedures contained in OSHA Method ID-160 and NIOSH Method 7400 are essential for obtaining adequate employee exposure monitoring. Therefore, all employers who are required to conduct monitoring are required to use these or equivalent methods to collect and analyze samples (OSHA 1994). In NIOSH Method 7400, asbestos is collected on a 25 mm cellulose ester filter (cassette-equipped with a 50 mm electrically-conductive cowl). The filter is treated to make it... 

The use of electrical equipment in hazardous areas is covered by the National Electrical Code, NEPA 70 (2006), National Fire Protection Association standards NFPA 496 (2003) and NEPA 497 (2004), and OSHA standard 29 CFR 1910.307. The American Petroleum Institute Recommended Practices API RP 500 (2002) and API RP 505 (1997) should also be consulted. 

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