There are two main types of exposure to hazardous substances:
Acute ExposureRapid or instant exposure to dangerous amounts of a substance. Having concentrated acid splash on your arm is a good example of acute exposure, and I have a nice scar to prove it. Proper protective gear will reduce or eliminate the exposure.
Chronic ExposureExposure at a lower dosage over a longer period of time. Your body can get rid of a lot of crap, but some things build up in your tissues and create problems down the road. Lead poisoning from eating paint chips is a good example of chronic exposure. Over the years, the lead builds up and takes its toll on the nervous system.
There are four primary routes of entry or methods of exposure that can be controlled:
- The largest organ of your body, your skin acts as a first line of defense against exposure to pretty much everything, but it will allow many chemicals to pass through into the tissues below.
- Cuts, scrapes, and other wounds must be covered when working around even fairly benign chemicals. Getting salt or vinegar in a cut hurts because it is doing damage to the tissue under the skin.
- Be careful when working with glass labware, as it tends to break at the worst time. Glass resists most chemicals and is easy to clean, so a lot of labware is fragile and prone to making very sharp edges when it breaks.
- Since your hands are generally going to be the closest part of your body to the chemicals, wear appropriate gloves. Latex gloves will work for most household chemicals (nitrile is better and not much more expensive), but you'll need to find something better if you're going to be playing with petroleum products. A good overview of how to select your gloves can be found here.
- Wearing a vinyl apron and shoe covers keeps the nasty off of your clothes, and prevents it from being carried to another location.
- Sanitation is vital. Wash your hands well after working with anything dangerous. Change clothes as soon as possible, and wash everything that came in contact with chemicals. Keep the work space clean to prevent accidental mixing of reactive chemicals.
- You have to breathe, even when working in a lab. Keeping the dust and aerosols out of your lungs requires anything from a dust mask to full-face respirator. I covered respirators pretty thoroughly in this article.
- Working with really nasty stuff should be done under a “hood”, which is a box with only one open side and a good fan pulling air out of it. The constant flow of air in through the opening (which you work through) pulls any dust, droplets, or fumes away from you. Make sure the exhaust is vented into a safe space, away from other people.
- Depending on the nature of the chemicals you're playing with, glasses with side shields are a minimum for safety; goggles are uncomfortable but safer, and face-shields work well to stop splatters from finding their way to your eyes.
- Your damp, open eyeballs have a direct connection to your brain via the optic nerve. They're also fairly delicate and easily damaged, causing horrible pain if injured. Being blind in normal society sucks -- now imagine being blind in an emergency.
- If you're around chemicals that are hazardous in any way, it is wise to avoid eating, drinking, smoking, or chewing gum. Ingesting things is what your mouth is for, but it also makes for a quick route to your blood stream. This is why nitroglycerin pills are placed under the tongue of someone having a heart attack: it gets into the bloodstream almost immediately.
- A bandanna around your face or a dust mask will keep unwanted things out of your mouth, while giving some protection to your lungs as well.
Always Be SafeI realize that this may be overly simplified, but I want you to actually think about the basics of your own safety.
- Do some research on the chemicals you're going to be playing with, especially if they are of the “highly energetic” type.
- Know what you can and can't mix together to avoid extremely rapid reactions that can hurt or kill you.
- Ask questions if you can't find the answers on your own. There are a lot of resources available, most of them online.