Hazards cost avoidance

There is both need and opportunity for safety professionals to be perceived as providing a valued consultancy that produces economic benefits, as well as improving safety. Those benefits, in addition to reduced costs for injuries and illnesses, are measured by the costs avoided by not having to retrofit to remove hazards brought into the workplace and by improved productivity and cost efficiency. 

This is a location which is continuously contaminated with explosive gases, chemical vapours or volatile liquids and thus is highly susceptible to fire hazards. Installation of electrical machines in such areas should be avoided as far as possible, to reduce cost, facilitate maintenance and take other precautions. 

Air stripping is used to remove 90% of the toluene (molecular weight = 92) dissolved in a 10 kg/s (159 gpm) wastewater stream. The inlet composition of toluene in the wastewater is 500 ppm. Air (essentially free of toluene) is compressed to 202.6 kPa (2 atm) and bubbled through a stripper which contains sieve trays. In order to avoid fire hazards, the concentration of toluene in the air leaving the stripper is taken as 50% of the lower flammability limit (LFL) of toluene in air. The toluene-laden air exiting the stripper is fed to a condenser which recovers almost all the toluene. A schematic representation of the process is shown in Fig. 2.11. Calculate the annual operating cost and the fixed capital investment for the system. The following physical and economic data are available ... 

Such sentinel workflow uses a prediction to select compounds for a more expensive screen that can confirm predicted hazards (liabilities, such as toxicity). It is, provably, the best workflow in contexts where a low prevalence of the hazard is anticipated, and where there is a backstop means further downstream (e.g., preclinical toxicity testing) for detecting hazards before humans are exposed. This workflow then allows the compounds predicted as safe to bypass the expensive hazards screen, without unacceptable risk, and can add significant value in terms of external screening costs or avoiding use of what may be a bottleneck resource. 

As a cautionary note PTC should not be considered a panacea for all of the problems associated with green chemistry. Two-phase reactions involving water are often difficult to deal with industrially, particularly if the water is contaminated with trace amounts of hazardous organic substances. In some cases it may be more practical, cost effective and environmentally prudent to avoid production of aqueous waste in favour of a recyclable less benign solvent. 

Consider the case of the production of peroxy esters (e.g. tert-buty] peroxy 2-ethyl hexanoate), based on the reaction between the corresponding acid chloride and the hydroperoxide in the presence of NaOH or KOH. These are highly temperature sensitive and violently unstable, and solvent impurities are detrimental in their applications for polymerization. Batch operations to produce even 1000 tpa will be unsafe. A continuous reactor can overcome most of the problems and claims have been made for producing purer chemicals at lower capital and operation cost the use of solvent can be avoided. Continuous reactors can produce seven to ten times more material per unit volume than batch processes. Since the amount of hazardous product present in the unit at any given time is small, protective barrier walls may be unneccessary (Kohn, 1978). 

H. Safety considerations. The Occupational Safety and Health Administration (OSHA), US Department of Labor, standard entitled Occupational Exposure to Hazardous Chemicals in Laboratories (29 CFR 1910.1450) makes it necessary to address safety issues in the SOP. The standard requires laboratories that use hazardous chemicals to maintain employee exposures at or below the permissible exposure limits specified for these chemicals in 29 CFR Part 1910, Subpart Z. Hazards associated with any specific chemicals used in a method must be addressed so that the user has the information needed to follow the Chemical Hygiene Plan for their laboratory. The method developer should limit the use of hazardous chemicals where feasible. The use of toxic and/or carcinogenic reagents should be avoided or eliminated as much as possible. Additionally, the cost of disposal is increasing and could impact the practicality of a method. Material Safety Data Sheets for the analyte(s) and any unusual or hazardous reagents should be provided for the user. 

The lack of information is well illustrated by trying to examine the costs and benefits of TSCA. The major benefits of the act are the adverse health effects avoided by whatever actions are taken under the act s authority or because of the act s existence. But for many actions, such as voluntary testing by industry, we are not sure whether to attribute the action to TSCA s existence. We also are not sure how to relate such actions to reduced exposure to potentially hazardous chemicals. Insofar as exposure is reduced, we usually do not have any precise idea of the health consequences of such reduced exposure. And even if we knew the health consequences we would not know how to place a dollar value on them. 

In many states, regulations only require that hospital incinerators not create a public nuisance usually recognized as odors and smoke opacity. Disposal costs for these medical wastes are becoming stiffer, just as surely as they are for infectious and other hazardous/toxic wastes. This adds another incentive to incinerate. It may be possible that a good deal of hospital waste could be separated, reduced, and recycled. While infectious waste is obviously not recyclable, the amount of waste designated infectious can be greatly reduced by separating materials to avoid excess contamination [74]. 

If anyone uses a chemical product (or preparation as defined by 2 of the Ordinance on Chemical Products), and in case such product (or preparation) can be replaced by a product (or preparation) that is less hazardous, but accomplishes the same or similar purpose, and does not entail an unreasonable additional cost, the more hazardous product must be avoided, i.e., it should not be used.26... 

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