PRINCIPLES OF TOXICOLOGY - Biology East Borneo

22.3 PROGRAM MANAGEMENT 531• Hazard-specific training to ensure they know how to work with the chemicals in ways whichwill minimize their exposures• Proper labeling of chemical containers, including the contents and the potential healthhazards, which enables workers to make the appropriate decisions• Effective engineering controls and proper personal protective equipmentHazard communication, or “right to know,” is considered the most far-reaching standard OSHA hasenacted, and, if fully implemented, will substantially increase the knowledge of toxic substances andworking conditions. Already, the right-to-know concept has been extended into the community setting,and also, to some extent, into the public sector. However, although this standard has been in effect forover 15 years, failure to comply with this rule is one of the most commonly cited OSHA violations.Before the rule was in place, labels and MSDSs (Material Safety Data Sheets) were notoriouslyincomplete, and substantial deficiencies remain today. For example, one recent MSDS limited the toxiceffects of a lead compound to “eye and skin irritation.” Indeed, since the labels and MSDSs are oftenprepared by those marketing the toxic substance, there may be a short-term incentive to minimize thedegree of hazard as advertised on the MSDS. The opposite also occurs. The preparer includes so muchinformation and always specifies the protective measures for worst-case situations in which the readershave difficulty determining the real hazards and appropriate levels of protection. In spite of theseproblems, many labels and MSDSs have gradually improved to the point where they are excellentquick reference guides to the current state of knowledge on a particular substance, including the latestanimal testing and epidemiological work. Ideally, the labels should be an abstract of what appears onthe MSDS, listing the important acute and chronic toxicity information (including target organs),exposure routes, necessary personal protective equipment, and the manufacturer.The right-to-know concept has been extended to include the more fundamental, and controversial,concept of allowing employees to change the way they do their jobs to reduce a hazard. A Canadianregulation, dubbed the “right to act,” extends the right-to-know concept accordingly.Hazard AssessmentThus far in this chapter industrial hygiene has been described broadly as the applied science devotedto understanding the interaction between exposure to chemicals and the potential hazardous effects.In the environment the manifestation of adverse health effects is minimized by eliminating or reducingexposure as much as possible. The multistep process of reducing exposures involves several distinctphases, including anticipation, recognition, evaluation, and control of exposures.Anticipation Anticipation of adverse health effects can be difficult. Successful anticipation usuallyinvolves an examination of the production process while it remains in the design phase. However, itcan also be applied to modifications of existing process, changes in ventilation characteristics, orincreases in production levels. Control measures are often most cost-effective at the stage of newprocess design, since disruptive retrofitting measures are avoided. Downtime is eliminated, andmachinery modifications can be included in space and other resource allocations. Opportunities forsubstituting a less toxic substance for a more toxic one are also usually more realistic at this stage,because changes in established, successful processes are resisted and capital costs may be high. In fact,substitution of less toxic compounds for more toxic substances is likely an important means for futureimprovements in both public health and environmental quality.But how does one anticipate a potential overexposure? The answer is to ask questions of the otherdisciplines involved in the design work. Engineers, architects, economists, and other planners aretypically focused on designing the most cost-effective means of production possible. Since the adverseeffects of chemical exposures are often not immediately obvious and stretch out over a number ofyears, they are usually overlooked in preliminary designs. Changes in process are usually dictated by