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types of chemical hazards

Types of Chemical Hazards and How to Manage Them

Industrial development and increasing demand for diverse goods and services to cater to the increasing whims and needs of humanity have resulted in chemicals being utilized in many products and processes. This has increased the chemical exposure of people, both at home and in the workplace. Therefore, exposure to chemicals and their harmful effects has spread across the globe at alarming rates causing a rise in health problems and negatively affecting worker safety.

Chemical hazards are mainly caused by the characteristics of chemical substances that may cause explosions, fires, or corrosions; or emit poisonous gases or mini particles. Often, chemical substances react negatively when exposed to, or mixed with, other materials or chemical substances. For instance, asbestos particles are usually dispersed in the atmosphere when moved.

Routes of Chemical Exposure

While the use of chemicals in processes, production, and goods have benefited people in many ways, these chemical substances are also the cause of chemical hazards. There are several routes of chemical exposure as described below.

  • Inhalation – that is breathing in toxic vapors or small chemical particles
  • Absorption – such as direct exposure to the skin by touching a chemical substance without any protection such as wearing gloves.
  • Injection – that is when a sharp contaminated object or needle accidentally penetrates a worker’s body (such as hand or foot)
  • Ingestion – that is when toxins are accidentally swallowed

Human biology allows chemicals and other toxic substances to enter the body in different ways. The most common is inhalation when harmful gases are present in the atmosphere. Another is through direct contact of the skin with the hazardous substance. Injection of a hazardous chemical or contaminated substance is possible is if employees are working in laboratories or medical facilities dealing with contaminated needles and other infectious materials. Ingestion is the fourth method, but it is a less common form of exposure in the workplace.

Types of Chemical Hazards in the Workplace

There are several types of chemical hazards in the workplace. While there are several classifications for these chemical hazards, many of these hazardous chemical substances fall within several of these classifications.

Respiratory protection againsts AsphyxiantsAsphyxiants

Chemical asphyxiants deprive the body of oxygen; interrupting the transfer and use of oxygen by the bloodstream.

Asphyxiant Chemical Examples: Carbon monoxide and cyanide.


Corrosive ChemicalsCorrosives

Chemical corrosives cause visible and/or irreversible changes to the composition of a material due to direct contact. Similarly, these can also cause a localized reaction in the human body at the point of contact. However, corrosive chemicals also have the potential to produce systemic chemical exposure away from the point of contact when mixed with other substances.

Corrosive Chemical Examples: Sulfuric acid and sodium hydroxide.


Chemical hazards that are classified as irritants cause harm to the eyes, skin, or respiratory tract of a person. Irritants are either highly, moderately, or slightly water-soluble. The hazards can manifest as redness, rashes, inflammation, coughing, or hemorrhaging. Irritants are mostly short-term severe illnesses but can also have long-lasting side effects in some people. People can also have an allergic reaction to some of these chemical materials with long-lasting health impacts or even be fatal.

Irritant Causing Chemical Examples: nickel chloride and chromic acid.


Sensitizers are also known as allergens meaning they cause an allergic reaction in people who face repeated exposure over time to certain chemicals. Reactions to chemicals deemed as sensitizers vary from person to person and can be either acute or chronic. Chemical exposure can manifest as swelling of the airway or develop into dangerous illnesses such as lung disease. Some diseases such as asthma and contact dermatitis become common among people due to over-exposure to chemicals.

Allergen Causing Chemical Examples: Chlorine and alkalis.


Carcinogens are cancer-causing chemical substances, and a small amount of such a chemical is enough to severely harm human health. The hazards of such chemical substances will only appear many years after the exposure. There are over 200 known human carcinogens.

Chemical Carcinogen Examples: Benzene, cadmium, formaldehyde, and vinyl chloride.

GHS labels for chemical safetyMutagens

Chemicals classified as mutagens cause genetic changes to a cell’s DNA and RNA. Genetic changes can cause cancer, prevent normal biological functions, or may result in the malfunction of a particular organ. Examples: Benzene, ionizing radiation, and hydrogen peroxide.


Hazwoper trainingTeratogens

Chemical teratogens can disrupt the normal development of a fetus causing birth defects and even the healthy advancement of pregnancy.

Chemical Teratogen Examples: Thalidomide, ionizing radiation, and organic mercury compounds.

chemical hazardReactive

Chemical substances that cause a chemical hazard such as an explosion when mixed or combined with other chemical or non-chemical substances such as water or air.

Reactive Chemical Examples: Nitric acid, benzoyl peroxide, and silane.

Managing Workplace Chemical HazardsFlammable

Many chemicals are characterized as flammable as they can easily burn or ignite when exposed to oxygen.

Flammable Chemical Examples: Methanol, acetone, propane, and butane.


For a complete list of workplace chemicals and their hazards, refer to the NIOSH Pocket Guide to Chemical Hazards (NPG).

Managing Workplace Chemical Hazards

The Occupational Safety and Health Administration (OSHA) guides employers to protect employees in the workplace from chemical hazards. Using the strategy of the Hierarchy of Controls, developed by the National Institute for Occupational Safety and Health (NIOSH), the recommendations from the most effective to the least effective ways to control chemical hazards are as follows:

  • Elimination/Substitution – where the need for hazardous chemical usage is completely removed or an alternate less or non-hazardous chemical is used.
  • Engineering Controls – where employers must implement changes that are physical to the workplace that helps to reduce exposure to the chemical hazard on the workers using or handling hazardous chemical substances.
  • Administrative and Work Practice Controls – changing how a work task is performed or establishing efficient workplace policies, protocols, processes, and control and monitoring mechanisms.
  • Personal Protective Equipment (PPE) – using PPE such as respirators, gloves, protective full-body suits, etc., can help in reducing the workers’ direct contact with the hazardous chemical.

In addition to implementing the Hierarchy of Controls, employers can also benefit from following OSHA’s guidelines on Permissible Exposure Limits (PELs) for chemical hazard exposures to workers. NIOSH has provided  Recommended Exposure Limits (RELs), while the American Conference of Governmental Industrial Hygienists (ACGIH) gives guidance in the form of Threshold Limit Value (TLVs) and Biological Exposure Indices (BEIs). Read more here.

OSHA also recommends hazard communication in the form of labeling containers, putting up safety signs, using pictograms, and developing safety data sheets. OSHA’s Hazard Communication Standard aids employers and employees in better understanding chemical hazards in the workplace and identifying and implementing methods to minimize and control workplace chemical hazards. The Standard also recommends training for employees handling hazardous chemicals as part of their regular work tasks as well as during emergencies when spills or exposures to chemical substances can occur in the workplace.

Online Training Courses for Chemical Hazards

The OSHA 40 Hour HAZWOPER online training course provided by us gives comprehensive training on understanding, identifying, and managing chemical hazards in the workplace. Other courses such as the 24 Hour TSDF Operations online training also offer an understanding of proper hazardous chemical substance usage and what constitutes chemical hazards. Find our entire course list on the HAZWOPER-OSHA home page.

Enroll today and ensure the health and safety of your workers!

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