Common hazards

Remember to treat all compounds, especially new materials, with care. Avoid breathing vapours and do not allow solids or solutions to get on your skin. The majority of accidents are caused by a few common hazards. Some of the most frequently encountered dangers are listed in Table 2.1 and you should be aware of all of these, and always take appropriate precautions. Consult safety manuals and other Sections of this book for more information. Throughout the book safety warnings are highlighted in bold italic text. 

Electrical equipment Danger of fires caused by electrical sparks with solvent vapours, and a risk of electrocution with badly maintained equipment 

Glassware Danger of cuts, leaks of harmful compounds 

Solvents Most are extremely flammable Benzene, halogenated solvents are toxic 

Gas cylinders May leak harmful gases or discharge violently (Chapter 7) 

---

The most common hazards control technique is a checklist. The checklist is prepared by experienced personnel who are familiar with the design, construction and operation of similar facilities. Checklists are relatively easy to use and provide a guide to the evaluator of items to be considered in evaluating hazards. API RP 14J has examples of two checklists which can be used to evaluate facilities of different complexity. Because production facilities are very similar and have been the subject of many hazard analyses, a checklist analysis to assure compliance with standard practice is recommended for most production facilities. The actual procedure by which the checklist is considered and the manner in which the evaluation is documented to assure compliance varies from case-to-case. 

For the second edition of this book, I added more incidents, extended the sections on Bhopal and Mexico City, and added chapters on some little-known but quite common hazards and on accidents in computer-con-trolled plants. 

Table 8.3 provides general guidance for handling compressed gases. Selected common, hazardous compressed gases are discussed below. 

Corrosive wastes are acidic or alkaline (basic) wastes which can readily corrode or dissolve flesh, metal, or other materials. They are also among the most common hazardous wastestreams. Waste sulfuric acid from automotive batteries is an example of a corrosive waste. U.S. EPA uses two criteria to identify corrosive hazardous wastes. The first is a pH test. Aqueous wastes with a pH greater than or equal to 12.5, or less than or equal to 2 are corrosive under U.S. EPA s rules. A waste may also be corrosive if it has the ability to corrode steel in a specific U.S. EPA-approved test protocol. 

A common hazard in the handling of explosives is for them to be subjected to the effects of a blow which is to some extent at a glancing angle. This corresponds neither to pure impact, nor to pure friction. A corresponding simple and useful test for the safety of an explosive during handling is the torpedo friction test illustrated in Fig. 6.8. In this, a torpedo... 

Normally, a what-if/checklist analysis is used to examine the potential consequences of accident scenarios at a more general level than some of the more detailed PrHA methods. It can be used for any type of process at virtually any stage in its life cycle. However, this method is generally used to analyze the more common hazards that exist in a process. 

Toxic substances can also be encountered in debris. For example, hazardous chemicals may have been legitimately stored in a blown up building or there could be lead from the batteries of bomb damaged motor vehicles. Another common hazard is the presence of asbestos in old buildings. 

Common hazardous wastes include (a) waste oil, (b) solvents and thinners, (c) acids and bases/alkalines, (d) toxic or flammable paint wastes, (e) nitrates, perchlorates, and peroxides, (f) abandoned or used pesticides, and (g) some wastewater treatment sludges. Special hazardous wastes include (a) industrial wastes containing the USEPA priority pollutants, (b) infectious medical wastes, (c) explosive military wastes, and (d) radioactive wastes or releases. 

Table 1 Methods for Disposal of Small Quantities of Common Hazardous Wastes... 

When they are used as solvents in reactions for example, most organic reactants are not soluble in water but are soluble in a variety of organic liquids, many of which are toxic or hazardous in other ways. Some of the most common hazardous solvents are... 

This Is a common hazard in the handling of expls. In this test, a. torpedo weighing 0.5 to 5kg, slides down an inclined plane at an angle 70 or 80° to strike the expl resting on an anvil. The head of the torpedo and the material of the anvil can be varied, as well as the height of fall. Some results of tests are shown intTable 6.1 on p 76... 

Advance planning for the possibility of an accident will greatly minimize the consequences. A common hazard is found when a bench scale operation is scaled up when this scale-up occurs in an overutilized laboratory area. Solvents in small and large quantities may be found in the immediate vicinity and batches of oxidizers, expls and similar hazardous ingredients may be present where they may be exposed to ignition by one or more mechanisms. Often other personnel are present within the structure not knowing of the potentially hazardous operations which are conducted in their immediate vicinity. Exits and walk-ways may be blocked by materia-als, equipment or personnel in transit. While there is no safe expl, proplnt or pyrot material, familiarity does breed complacency. We are reminded of a recent expl of a BlkPdr replica plant (Ref 80) which resulted in the loss of life and the destruction of the plant. Nevertheless,... 

Octanol/Water Partition Coefficients for Common Hazardous Compounds... 

Vapor Pressure and Henry s Law Constants for Common Hazardous Chemicals... 

Table 3 Reference doses of some common hazardous compounds.

Sources of Uncertainties in Risk Assessment Table 4 Slope factors of some common hazardous compounds. 13... 

Genium s Handbook of Safety, Health, and Environmental Data for Common Hazardous Substances. Genium Publishing Corporation (1999). Schenectady, NY McGraw-Hill (ISBN... 

The most common hazard for exposure to crystalline silica occurs with sandblasters who use sand for cleaning of surfaces, thus generating dust clouds of freshly fractured crystalline silica. Other occupations include farm labor where mineral dusts are generated... 

Herbal therapies expose patients to potential hazards. Common hazards are ... 

---