CHAPTER 4: How You are Exposed to Chemicals, and What are the Proper Steps to Avoid/Minimize Exposure?

4.0 Introduction
The primary goal of this Safety Manual is to provide policies and guidelines that, when properly followed, protect persons from harmful exposure to hazardous chemicals.  This chapter will provide an overview of how you can be exposed to a chemical, and steps to take to avoid or minimize exposure to chemicals.


4.1 Routes of Exposure
If you understand how you can be exposed to chemicals then you can better protect yourself from becoming exposed.  Exposure to chemicals can occur by four main routes: inhalation, contact with skin or eyes, ingestion, and injection. 

4.1.a Inhalation.
In addition to those substances that are in gas phase at ambient room temperature and pressure, many liquids and solids can give off harmful vapors or fumes.  Also, fine powders can become airborne as dust particulates, and liquids can be shaken or atomized into a fine mist.  Gases, Liquids, and Solids may also produce smoke when their vapors are ignited.  If these substances are inhaled, the body can suffer physical damage to the mouth and respiratory system, or these substances can be absorbed into the blood and distributed to various internal organs.

4.1.b Contact with Skin or Eyes.
In addition to being inhaled, vapors, fumes, or mists can come in contact with the skin or eyes and produce harmful results (think of how your eyes can water and hurt from simply peeling an onion).  Chemicals obviously can come in direct contact with the body, so proper procedures and PPE must be used.  Even if a chemical is not particularly harmful if it touches the skin, care must still be taken because the chemical can seep into the body through “insignificant” cuts in one’s skin.

4.1.c Ingestion.
Chemicals that are on a person’s hands can be ingested if the person touches his/her mouth or contaminates food items with unwashed hands.  Food items that are brought into a laboratory can absorb chemicals.  Ingestion of chemicals should not occur if proper personal hygiene practices are followed.

4.1.d Injection.
Chemicals that are on the surface of a sharp object (or an object that can be broken and stuck into the skin, such as a glass pipet), can be introduced into the body if the contaminated object accidentally penetrates the skin.