Static electricity hazards

Dust Explosions Static Electricity Hazards of Vacuum Hazards of Inert Gases Gas Dispersion... 

Static electricity hazards and nuisances are typified by the generation of large potentials (0.1-100 kV) by small charging currents (0.01-100 pA) flowing in high resistance circuits (10 -10 Q). This in part differentiates static electricity from other electrical phenomena. For example, stray currents in low resistance circuits are typically of the order 1 A for potential differences of the order 1 volt (A-4-1.3). The electric field at any point in relation to a conductor is proportional to its potential, while magnetic field is proportional to... 

Velocity of liquid in pipes versus static electricity hazards. Vapour venting and gas balancing. 

Saletan, D. L., The Theory Behind Static Electricity Hazards in Process Plants, June 1, 1959, p. 99. 

Rat, R., and Isler, J. (1995) The static electricity hazards method for assessing pyrotechnics sensitivity and approach for hazard reduction. Proc. 26th Inti. Ann. 

Dukek, W.G., et al., Static Electricity Hazards in Aircraft Fuel Systems, Air Force Aero Propulsion Laboratory Report AFAPL-TR-78-56, August 1978. 

Saletan, D.I., How to calculate and combat static electricity hazards in process plants II, Chemical Engineering, pp. 101-106, June 1959. 

The explosive ingredient in Sinoxyd-type primers is lead styphnate (lead trinitroresorcinate), which is very sensitive to static electricity, and fatalities have resulted from handling the dry salt. Preparation of the pure salt is difficult, and many patented preparations, including basic modifications, exist. Some claim special crystalline forms and/or reduced static electricity hazard. Explosive ingredient substitutes for lead styphnate were sought that would be easier to make and safer to use. These included lead azide, diazonitrophenol, lead salts of many organic compounds, complex hypophosphite salts, pic-rate-clathrate inclusion compounds, and pyrophoric metal alloys. 

In 1962 Kenney applied for patents on many complex, basic lead pic-rate-clathrate inclusion compounds which did not have the static electricity hazard of lead styphnate. Of 44 compounds listed in his patent, monobasic lead picrate-lead nitrate-lead acetate was preferred for primers, although monobasic lead picrate-lead nitrate-lead hypophosphite dibasic lead pic-rate-lead nitrate-lead acetate and monobasic lead picrate-lead nitrate-lead acetate-lead hypophosphite were also suitable. Glass was thought to damage the bore of the firearm and was considered by some to be undesirable. A glassless rimfire mixture was ... 

Note A discussion of the pneumatic loading system and the hazards involved is presented in the DuPont Technical Bulletin, entitled "Static Electricity Hazards and Their Con-... 

The MIE is particularly relevant in ignition by sparks. Typical values have been shown to be 30,120, and 50 mJ for sugar, cocoa, and coal, respectively, and are strongly dependent on the particle size the finer the dust, the more easily it can be ignited [11]. The main application of MIE is in relation to the static electricity hazard. It has been reported that the majority of incidents occur with sparks having ignition energy below 25 mJ [13]. 

Employers must make sure that each affected employee uses protective footwear when working in areas where there is a danger of foot injuries due to falling or rolling objects, or objects piercing the sole, or when the use of protective footwear will protect the affected employee from an electrical hazard, such as a static-discharge or electric-shock hazard, that remains after the employer takes other necessary protective measures. 

Sturdy safety shoes should have impact-resistant toes and heat-resistant soles to protect against hot work surfaces common in roofing, paving, and hot metal industries. The metal insoles of some safety shoes protect against puncture wounds. Safety shoes may also be designed to be electrically conductive to prevent the buildup of static electricity in areas with the potential for explosive atmospheres, or noncon-ductive to protect workers from workplace electrical hazards. All safety shoes must comply with the ANSI standard(s) mentioned above. In addition, depending on the types of worker exposures, there may be a need to provide specially designed safety shoes such as conductive or electrical-hazard safety shoes. 

In addition to revising the Electric Power Generation, Transmission, and Distribution, and the Electrical Protective Equipment standards, OSHA also revised the General Industry Foot Protection standard to clarify that an employer must ensure that workers use protective footwear as a supplementary form of protection when the use of protective footwear will protect the workers from electrical hazards, such as static-discharge or electric-shock hazards, that remain after the employer takes other necessary protective measures. 

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