Toxicology is a field of science that helps us understand the harmful effects that chemicals, substances, or situations, can have on people, animals, and the environment. Some refer to toxicology as the “Science of Safety” because as a field it has evolved from a science focused on studying poisons and adverse effects of chemical exposures, to a science devoted to studying safety. (n.d.)
Toxicology is intrinsically related to occupational diseases. Many workers develop occupational diseases due to long-term exposure to chemicals, radioactive materials, and other harmful substances.
As such, today’s workers are better safeguarded from toxic substances in the workplace. However, progress has also brought about new occupational diseases and hazards, and exposed workers to new types of toxic gases, chemicals, and other substances that have been discovered or manmade over the years. These newly emerging toxins continue to plague workers causing new health risks and health effects even as state-of-the-art techniques are used to analyze the effect of these chemicals on human health.
Respiratory diseases
Contact dermatitis
Musculoskeletal disorders
Mental disorders
Cardiovascular diseases
Occupational cancers
When employers embark on workplace risk-assessment to identify possible toxin contamination in work areas, exposure of workers to toxic substances and develop methodologies to safeguard workers from adverse impacts from pollutants, the following factors must be considered.
The length or period of exposure to the chemical toxin;
The dose (i.e. amount) of substance exposure; Pre-existing medical conditions; The metabolism of the individual;
Allergies and drug reactions;
The method of exposure
– inhalation, ingestion,
injection, and absorption; and
Gender, age, weight, etc.;
An individual’s habits (smoking, medication use, alcohol consumption nutritional intake, etc.);
Type of exposure – direct or indirect exposure, acute exposure, chronic exposure, or accidental
Accordingly, OSHA has developed Occupational Exposure Limits (OELs) for different air-borne toxins related to a range of occupations, industries, chemicals, and toxic substances. While stipulating Permissible Exposure Limits (PELs) which are based on 8-hour timeweighted averages (TWA), OSHA also specifies Ceiling and Peak limits which must be compulsorily adhered to by employers. While many of the details are available in the applicable sections of the General Industry, Construction, Shipyard Employment, Marine Terminals, and Longshoring regulatory standards, the most up-todate information is available as an Annotated Table.
OSHA’s requirement to train workers before they start work at construction sites and other worksites exposed to hazardous substances ensures that employees will receive relevant training on toxicology. The subject of toxicology is covered in several of our training courses such as the HAZWOPER 40 Hour, the HAZWOPER 24 Hour, and the H AZWOPER 8 Hour Refresher. Aspects of toxicology related to different hazardous substances such as asbestos and hydrogen sulfide are included in subject-specific training courses developed by us.
