Hazard experience

Meanwhile, members of the Medical and Related Problems Committee of the Chemical Corps Advisory Council were busy creating some of their own rules. They separated hazardous from non-hazardous experiments so that only the latter would require higher-level approval. They sought blanket approval for experiments already in progress, hoping to avoid unnecessary red tape. The Council made informed consent essential, however, and demanded sufficient evidence be made available to show that the soldier was tmly able to freely volunteer. 

Insurance companies have developed several strategies to cope with the information difficulties that lead to moral hazard and adverse selection. They use deductibles and copayments to reduce moral hazard. If cusfomers musf pay some of fhe damage cosfs themselves when accidents occur, they are less likely to engage in unanticipated risky behavior. Some firms also use experience rafing (i.e., raising rates if a claim is made) to reduce moral hazard. Experience rating penalizes cautious clients who still suffer accidents, but insurance firms cannot economically differentiate those careful policyholders from morally hazardous ones. 

Caution Higher temperature (500-700°C for graphite, 400-450°C for charcoal) can cause severe expiosions and formation of CF4, CjFg and other perfluorinated hydrocarbons. Thus fiuorination of graphite should be regarded as a potentially hazardous experiment. 

Existing hazards Experience from operators and maintainers (and, if available, any Hazard Log) can provide valuable guidelines relating to concerns and desired characteristics of each zone. 

Heavy leather gloves should be worn if it is necessary to reach behind a shielded area while a hazardous experiment is in progress or when handling reactive compounds or gaseous reactants. Proper planning of experiments should minimize the need for such activities. 

PPE only provides a barrier between the worker and the hazard." Experience shows that when some workers put on their PPE, they also don a "Superperson" mentality. What does this mean Often, when workers use eye, hand, foot, head, hearing, or respiratory protection, they take on an "I can t be touched" attitude. They feel safe, as if the PPE somehow magically protects them from the hazard, so they act as if they are protected, are invincible, are beyond injury. They feel, however illogically, that they are well out of harm s way. Nothing could be further from the truth. 

System safety typically applies the qualitative risk characterization method because for a large system with many hazards, it can become cost-prohibitive to quantitatively model, analyze, and predict the risk of each and every hazard. In addition, low risk hazards do not require the refinement provided by quantitative analysis. It may be necessary to conduct a quantitative analysis only on a select few high consequence hazards. Experience over the years has proven that qualitative methods are very effective, and in most cases provide decision-making capability comparable to quantitative analysis. Qualitative risk characterization provides a very practical and effective approach when cost and time are concerns, and/or when there is very little supporting data available. The key to developing a qualitative risk characterization approach is by carefully defining severity and mishap probability categories. 

Hazard experience in road traffic. - There are also various well-known studies on road traffic, in which the recognition and assessment of risks has been examined, both on normal traffic routes and on test routes (recently Quimby, 1983). Experience obviously plays an important role in these processes. Barrett Thornton (1968) already suspected that young drivers are more... 

In an experiment, a slight excess of the hydride is employed to ensure the complete reduction the unused hydride must then be destroyed. This can be done by the cautious addition of (rt) water, or (6) ordinary undried ether, which will ensure that the supply of water is both small and gradual, or (c) an ester such as ethyl acetate, which will be reduced to ethanol. The first of these methods, namely the addition of water, is hazardous and should be avoided. 

Other sources of hazard arise from the handling of such chemicals as concentrated acids, alkalis, metallic sodium and bromine, and in working with such extremely poisonous substances as sodium and potassium cyanides. The special precautions to be observed will be indicated, where necessary, in the experiments in which the substances are employed, and will also be supplied by the demonstrator. The exercise of obvious precautions and cautious handling will in most cases reduce the danger to almost negligible proportions. Thus, if concentrated sulphuric acid should be accidentally spilled, it should be immediately washed with a liberal quantity of water or of a solution of a mild alkali. 

Primary human skin irritation of tetradecanol, hexadecanol, and octadecanol is nil they have been used for many years ia cosmetic creams and ointments (24). Based on human testing and iudustrial experience, the linear, even carbon number alcohols of 6—18 carbon atoms are not human skin sensitizers, nor are the 7-, 9- and 11-carbon alcohols and 2-ethylhexanol. Neither has iudustrial handling of other branched alcohols led to skin problems. Inhalation hazard, further mitigated by the low vapor pressure of these alcohols, is slight. Sustained breathing of alcohol vapor or mist should be avoided, however, as aspiration hazards have been reported (25). 

Most of the techniques for determining risk or identifying hazards that are discussed herein require analysis by committee. The committee must be formed from individuals having specific and relevent experience to the chemical process under consideration. Furthermore, the management of this committee is paramount to the success of the project. Members must focus on the problem at hand and continue to make satisfactory progress. 

There are a large number of standard methods suitable for each stage in the hazard analysis and risk assessment procedure. The selection of the proper method depends on several factors. Some of these are the type of process, the stage in the lifetime of the process, the experience and capabiUties of the participants, and the step in the procedure that is being examined. Information regarding the selection of the proper procedure is available in an excellent and comprehensive reference (1). 

Hazard analysis does have limitations. First, there can never be a guarantee that the method has identified all of the hazards, accident scenarios, and consequences. Second, the method is very sensitive to the assumptions made by the analysts prior to beginning the procedure. A different set of analysts might well lead to a different result. Third, the procedure is sensitive to the experience of the participants. Finally, the results are sometimes difficult to interpret and manage. 

For chemical faciUties in the United States, hazard analysis is not an option if inventories of hazardous chemicals are maintained in amounts greater than the threshold quantities specified by the Occupational Safety and Health Administration (OSHA) regulation 1910.119. Many faciUties are finding that hazard analysis has many benefits. The process or procedure often works better, the quaUty of the product is improved, the process experiences less down time, and the employees feel more comfortable in the work environment after a hazard analysis has been completed. 

Hazard and Operability Analysis. The hazard and operabihty analysis (HAZOP) procedure is quite popular because of its ease of use, the abihty to organize and stmcture the information, minimal dependence on the experience of the analysts, and the high level of results. Furthermore, the approach is capable of finding hazards associated with the operation of a faciUty, hence the incorporation of the word operabihty in the name. 

Pilot plants are often more hazardous than process plants, even though they are smaller ia size, for many reasons. These iaclude a tendency to relax standard safety review procedures based on the small scale, exceptionally qualified personnel iavolved, and the experimental nature of the research operations the lack of estabhshed operational practice and experience lack of information regarding new materials or processes and lack of effective automatic iatedocks due to the frequendy changing nature of pilot-plant operations, the desire for wide latitude in operating conditions, and the lack of hill-time maintenance personnel. 

The need for skill and experience on the part of sample designers and persoimel cannot be overemphasized in chemical plant sampling. Safety precautions are of the utmost importance. Necessary steps must be taken to document the hazards involved in an operation and to ensure that the staff are weU-trained, informed, protected, and capable. Except for bulk powder sampling, most chemical plant sampling is hazardous and difficult and must be designed with care. The following discussions are based on the assumptions that most of these decisions have been made and a satisfactory sampling procedure has been planned. 

Risk characterization is defined as the integration of the data and analysis of the above three components to determine the likelihood that humans wiU. experience any of the various forms of toxicity associated with a substance. When the exposure data are not available, hypothetical risk is characterized by the integration of hazard identification and dose—response evaluation data. 

Inhalation toxicity does not present a hazard because of low vapor pressure. DGEBPA-based resins have been reported to cause minimal eye irritation (44). Systemic toxicity has not been noted in experiments where DGEBPA-based resins have been fed to laboratory animals. Mutagenic activity has not been shown in animals, but in vitro mutagenicity tests have yielded variable results (44). 

Past experience has shown that cryogenic fluids can be used safelv in industrial environments as well as in typical laboratories provided all facihties are properly designed and maintained, and personnel handling these fluids are adequately trained and supeiwised. There are many hazards associated with ciyogenic fluids. However, the principal... 

Reactive Hazard Review Reactive hazards should be evaluated using reviews on all new processes and on all existing processes on a periodic basis. There is no substitute for experience, good judgment, and good data in evaluating potential hazards. Reviews should include ... 

For example, in rotary vacuum dryers it is possible to prevent the formation of explosible dust-air mixtures by setting and monitoring a certain partial vacuum (negative pressure). This pressure value must be determined by experiment for each type of dust. With pressures of less than O.I bar, in general, hazardous effects of dust explosions need not be anticipated. If the vacuum system malfunctions, the partial vacuum must be released by inert gas and the instaUation shut down. 

The standard operating procedures demand great attention as they reflect personnel safety issues, safe operating limits and quality considerations. They should be written simply and clearly. The level of detail is determined by the training and experience of the operations staff but should also take into account the hazards inherent in the process. 

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