Confined spaces hazards with

The contractors SSAHPs at Sites B, F, and K had general confined space provisions but lacked site-specific confined space procedures. For example, SSAHPs for the Site K contractor and subcontractor had written confined space entry programs, but the programs did not establish site-specific rescue procedures or identify the confined space hazards present on the site. The job hazard analyses for both programs failed to address site maintenance tasks that could involve confined space entry and hot work hazards. The programs also failed to identify the specific person or position responsible for supervising confined space entry procedures and the location of permit-required confined spaces on site. Interviews with both contractors indicated confusion about rescue procedures. 

CHEMICAL PROPERTIES may polymerize easily polymerization may be hazardous usually contains inhibitors to prevent polymerization uninhibited monomer vapor may polymerize in vents and confined spaces reacts with strong oxidizing agents, alcohols, acids, amines, strong bases, iron, tin and copper reacts vigorously with water FP (-7°C, -19°F) LFL/UFL(5.3%, 26%) AT (534°C, 994°F) HF (-92.0 kJ/mol liquid at 25°C). 

All hazards are not addressed by the unwanted energy release concept. Examples are the potential for asphyxiation from entering a confined space filled with inert gas, or inhalation of asbestos fibers. But aU hazards are encompassed within a goal that is to avoid both unwanted energy releases and exposures to hazardous environments. Many authors have recognized the importance of Haddon s writings. 

Comply with other OSHA construction standards that address confined-space hazards. 

Employees must be trained to rmderstand the hazards they could encounter in the confined space, along with the methods used to control these hazards, and recognition of signs, symptoms, and characteristic effect of exposiu e to these hazards. TVaining is reqmred under 1926.1208(d) for PRCS, 1926.1216(b)(2) for CASA, and 1926.1217(b) for IHCS. 

A confined spaces rule for the construction industry proposed by OSHA in 2007 contains four classifications of confined spaces, each with its own protection requirements and hazard controls, instead of the two types currently identified by the agency. 

Chemical Reactivity - Reactivity with Water No reaction Reactivity with Common Materials Can catch fire when in contact with porous materials such as wood, asbestos, cloth, soil, or rusty metals Stability During Transport Stable at ordinary temperatures, however when heated this material can decompose to nitrogen and ammonia gases. The decomposition is not generally hazardous unless it occurs in confined spaces Neutralizing Agents for Acids and Caustics Flush with water and neutralize the resulting solution with calcium hypochlorite Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

F. All site control elements of the safety and health program must be fully implemented as described in the program. The purpose of site control requirements is to ensure that only properly trained and authorized individuals enter those areas of the site with potential hazards, and that, in the event of an emergency, rapid assistance can be rendered to employees working in the exclusion zone. This section discusses the findings of two components of site control the establishment and maintenance of site work zones and the establishment and implementation of appropriate confined space procedures. 

Special versions are available, such as hazard-proof and for high-pressure operation, but these are not normally applicable to the field of air conditioning. Fans are available with fewer blades (part-solidity) to allow the use of smaller higher-speed motors. There are also fans with short casings having a length little more than that to accommodate the blades for use in confined spaces. 

Injuries and fatalities from asphyxiation are often associated with personnel entry into inerted equipment or enclosures. Guidance on safe procedures for confined space access are provided by OSHA (OSHA, 29 CFR 1910.146, Confined Space Entry Standard, 2000), the American National Standards Institute (ANSI, Z117.1, Safety Requirements for Confined Spaces, 2003), Hodson (Hodson, Safe Entry into Confined Spaces, Handbook of Chemical Health and Safety, American Chemical Society, 2001), and BP (BP, Hazards of Nitrogen and Catalyst Handling, 2003). OSHA has established 19.5 vol % as the minimum safe oxygen concentration for confined space entry without supplemental oxygen supply (see Table 23-18). Note that OSHA imposes a safe upper limit on 02 concentration of 23.5 vol % to protect against the enhanced flammability hazards associated with 02-enriched atmospheres. 

A brief example helps If I have ajar containing gasoline it is a potential explosion hazard, or is it If the jar is sealed vapor tight, where s the hazard Now take the eap off the jar Is there a hazard If so, to whom The air blowing aeross the jar and the vapor pressure of the liquid will cause it to evaporate. Again, no problem — maybe or maybe not. However, if we are in a confined space with an source of ignition, there may be an explosion. Similarly, if the container falls off the shelf and releases the gas, there is an additional hazard which may lead to fire or explosion. 

Calcium hydride ignites in air on heating and can explode violently if mixed and rubbed with a strong oxidizing agent such as perchlorate or bromate. Contact with water produces hydrogen which can create a fire hazard in a confined space. 

Because biphenyl is often transported in the molten state, a moderate fire hazard does exist under these circumstances. Biphenyl, with a flash point of 113°C, has a lower flammability limit of about 0.6% (by volume) at the flash point to an upper limit of 5.8% at 166°C (42). Dust explosions are a hazard when vapors from a hot liquid surface condense in air in a confined space. 

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