10.1 Risk, Hazard and Exposure
What does it mean to be in a safe workplace?
The activities that are carried out in laboratories vary widely. Even within the boundary of what we might call a ‘chemical laboratory’ many different types of things might go on: synthetic chemists may be running chemical reactions, analytical chemists may be working with instruments for analysis, and biochemists might be working with organisms or natural compounds that are poisons. Similar activities occur in other laboratory and production spaces as well. Lab work supports health care, agriculture, the food and textile industries, mining and manufacturing.
The work in these spaces may carry risks to the personal health of those working in that space, and/or to the greater environment. While the particular concerns relevant to a specific lab vary, workplace safety in all laboratories can be considered using general guidelines and concepts.
The field of industrial hygiene includes frameworks that are useful as we consider these issues, and has certain ways to describe and consider safety and environmental health. These ideas can cross over into other working environments beyond what we think of as laboratory work as well.
To begin, it makes sense to get a shared vocabulary around safety. Some fundamental terms to understand include:
Hazard is a characteristic of a substance or experience that links it to the possibility of doing harm to an individual or the environment. Both in and out of the laboratory we are faced with hazards every day.
Risk is related but different, in that it incorporates the likelihood that such harm will occur. Risk is often described as the product of hazard and exposure to the hazard.
Risk = Hazard x Exposure
It is always good to minimize risk. It is difficult/impossible to minimize hazard, since hazards are intrinsic, a characteristic of a substance or event.
Exercise 10.1.1-6
Consider this familiar situation: Gasoline is a hazardous substance, which is not only dangerously reactive (flammable) but also highly toxic. Many of us don’t worry much about these hazards, however, because we don’t handle gas directly. We minimize risk by reducing exposure.
When we devise systems for handling a hazardous material like gasoline in order to reduce the risk to the public, gas station attendants, or the environment, we are working with what are called controls: methods to control risk. Controls are around us as we make our way through life. They come in various forms: some are more visible to us (like stop signs) while others are not (regulations that limit what type of vehicle can use the road). Many of these are not even recognized by us. For instance, the rules that govern the transportation of substances by train are many–and few people outside of that industry have taken the time to learn or pay attention to them.
We now will learn how to investigate hazardous materials, including how to think and communicate about the innate hazards associated with substances. Then we will turn our focus to controlling risk. The overall goal of this chapter is to give you a framework for thinking about hazard and risk so that you can work effectively and safely in potentially risky situations in chemical laboratories. The things you learn may also translate to other situations where there you encounter risks, as well.
