Handling Hazardous Gases

Most inert gases are simple asphyxiants. Their major hazard, which is especially severe when they are used indoors, is displacement of air and the creation of an oxygen-deficient atmosphere. 

Air normally contains 21% by volume oxygen. If this concentration is reduced to less than about 12%, humans will become unconscious almost immediately and with no warning. Death will follow quickly if oxygen is not restored. 

At oxygen concentrations of 15-16%, an individual becomes mentally incapable of diagnosing the situation and even euphoric, so that he will make no attempt to escape. Whenever oxygen concentrations fall below 19.5%, air-line masks or self-contained breathing apparatus is required. 

Details of accident prevention techniques are in CGA P-12 and CGA P-14. CGA SB-2, Oxygen-Deficient Atmospheres, is a good introduction for personnel. 

Medical gases include several of the common compressed gases as well as special mixtures. They often have high standards of purity and always require special precautions in preparation, packaging, handling, and use. These different aspects are covered in a series of codes. 

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Table 5.8 shows what a typical worksheet might look like for a laboratory that handles hazardous gases. Note that this worksheet includes a position for the facility risk index. As you can see, if the control is implemented, then the FRI changes. Again, it is very important to include verification of control. This is what ensures that your control is adequate to control the hazard, and it is something that can be verified to be in place. 

Unlike ECF, direct fluorination does not alter the carbon backbone preparation of isomerically pure acids is possible (18). Both direct fluorination and ECF permit a great variety of stmctures to be made, but each method is better at certain types of stmctures than the other. Ether acids are produced in good yields, by direct fluorination (17), while ECF of ether-containing acids is fair to poor depending on the substrate. Despite much industrial interest, the costs and hazards of handling fluorine gas have prevented commercial application of this process. 

Compliance with limits set for stocks of potentially hazardous chemicals Storage, segregation and handling of gas cylinders Display of appropriate warnings/notices... 

Handling hazardous ehemieals has beeome part of most people s everyday living. Just eonsider gasoline, and how most people fill their own tanks. In the manufaeturing arena, ehemieals are eommonplaee. On hazardous waste sites there are a variety of unknown ehemieal substanees and other hazards that may take the form of a solid, liquid, or gas. The eflfeets of exposure to toxie ehemieals may either be immediate (e.g., aeid burns) or delayed (e.g., lung damage from inhaling asbestos). There are four routes of ehemieal exposure that exist ... 

Red phosphorus will react with atmospheric moisture to form toxic phosphine gas and will ignite readily in air. As a result, the commercial product is often encapsulated in an appropriate polymer matrix. Suitable stabilization and encapsulation have led to commercial concentrates containing 50% red phosphorus. Handling hazards and the color of the final flame-retardant products may be a deterrent for wider use. 

Hydrogen Handling Hazards. The principal hazards associated with handling hydrogen as a gas or a liquid or a slush (mixture of solid and liquid hydrogen) are related to... 

Hazards Use caution when handling chlorine gas, and use proper ventilation. 

Hazards Wear gloves when handling 70% nitric acid. 70% Nitric is highly toxic and corrosive. Use proper ventilation when handling ammonia gas, or its solutions. 

Hazards Use caution when handling chlorine gas, which is toxic—avoid inhalation of the fumes. Extinguish all flames before using hexane, which is highly flammable. 

Hazards Use proper ventilation when handling chlorine gas, and avoid inhalation of vapors. Use proper ventilation when handling toluene. Sulfur chloride is irritating to the eyes, nose, and throat. Use proper ventilation when handling. Sulfur chloride may also be corrosive to tissue, so wear gloves when handling. Use proper ventilation when handling ammonia, and avoid inhalation of the vapors. 

Classification Liquefied petrol, gas Empirical C4H8 Formula CH2 CHCH2CH3 Properties Colorless liquefied gas sol. in most org. soivs. insol. in water m.w. 56.11 dens. 0.5951 (20/4 C) vapor pressure 50 psig (100 F) f.p. -185 C b.p. -6.3 C flash pt. -79 C Toxicology Asphyxiant gas handling hazards incl. fire, suffocation, and frostbite TSCA listed... 

Compressed gas hazards.Materials Handling Storage — Handling Compressed Gas Cylinders... 

Fluorine is a highly corrosive and hazardous gas and so is difficult to handle safely. As a result there are only a few companies that have the ability or desire to manufacture CFx in large quantities. 

Remove the valve from the cylinder only after making certain that the cylinder is empty and does not contain a hazardous gas. Cylinders containing flammable or toxic gas must be properly handled using an appropriate abatement system. 

This manual covers safety issues related to working on an oil and gas drilling and production site, as well as transport safety and compliance, on-road and off-road safety, loading and vmloading, handling hazardous materials, and safe transport operations. 

Fire and Gas Monitoring and Control. The last monitoring and control level handles hazards due to combustible or toxic gases. It may communicate with the process control system. Again, it is usually a passive system and requires periodic proof testing. When the response to an alarm includes partial evacuation of the site or activation of response teams, frequent drills and clear establishment of responsibility are necessary. 

ANSI/ASHR AE110-1995, Method of Testing the Performance of Laboratory Hoods, specifies a quantitative test procedure for evaluation of a laboratory fume hood. A tracer gas is released at prescribed rates and positions in the hood and monitored in the breathing zone of a mannequin at the face of the hood. Based on the release rate of the tracer gas and average exposure to the mannequin, a performance rating is achieved. NFPA 45, Standard on Eire Protection for Laboratories Using Chemicals, 2004 Edition, applies to laboratories that handle hazardous chemicals. 

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