It is such an interesting word, and there are so many definitions and connotations that go along
with it. Just to name a few:
1. the experience of coming into contact with some environmental condition
or social influence that has an effect, either harmful or beneficial
2. the harmful effects of cold or other extreme weather conditions
3. reporting of events by the broadcast or print media
4. the revelation of a scandal or of somebody’s secrets or private information
5. an amount of light permitted to fall on light-sensitive material such as film
or paper coated with emulsion
Encarta® World English Dictionary © 1999 Microsoft Corporation. All rights reserved.
Developed for Microsoft by Bloomsbury Publishing Plc.
You are being exposed to chemistry every time you go to lecture or go to lab or read
about chemistry. This is a good kind of exposure (hopefully). Unfortunately, everyday
you are also exposed to germs like viruses and bacterial infections; keyboards and
classmates and other things that you are in contact with everyday are obvious sources.
For chemists working in the lab, exposure is a constant threat that needs to be minimized.
If you are aware of the dangers, you can protect yourself, others, and even the
environment. Laboratory contact with chemicals, glassware, and other equipment will
expose you to certain things, and generally all foreign entities that come in contact with
your body could be damaging. Our goal is to make you aware of the potential harm so
that you can prevent this harm from happening to yourself and to others.
There are four main routes of exposure in chemistry
(and lots of other types) laboratories:
Physical Contact! (also called dermal absorption) – the main one!
Your skin is the largest organ you have, and it is your body’s first defense as far as chemicals are
concerned. Unfortunately, your skin surface area defines the area that needs to be defended, and it
is not a small area. Also note that your eyes are part of this surface area, since they are open
during the lab (or should be). Your fingers and hands are very vulnerable, since laboratories are
filled with hands on work. Your feet are particularly vulnerable (especially the tops of your feet)
because things fall down when they fall. Aprons, gloves, goggles (PPE) and wearing appropriate
laboratory clothing (closed shoes, sleeves, longer pants) are the best ways to minimize exposure
through contact. Save your epidermis! Clothes and shoes can be replaced.
In a lab with organic solvents, many things are volatile and easily move through the air. Those
solvents smell – ethyl acetate, methylene chloride, hexane – they are all smelly. And you will
smell like lab when you leave the lab. Volatile solvents evaporate quickly, which means that the
solvents become gaseous and move into the air. You smell chemicals because the molecules
move up your nose and hit recepto