What are the health effects of exposure to chemicals?

When handling or working with hazardous or non-hazardous chemicals, there is always the risk of exposure, whether via breathing, swallowing, or skin or eye contact. In some cases, exposure may be harmless, while in other cases it could result in severe adverse health effects or even death. 

In this article, we take a closer look at chemical exposure, what makes them harmful, and what the health effects associated with certain types of exposure might be.

What makes chemical exposure harmful?

As we say at Chemwatch, hazard does not equal risk. Just because a chemical may be hazardous, does not mean that there is a high risk of it causing adverse effects. Several factors work together to determine whether a given chemical will affect you negatively, including: 

The nature of the chemical

  • Is this chemical carcinogenic or mutagenic or classified as ‘Generally Recognised As Safe’ (‘GRAS’)?
  • What form is it in, e.g., powder, spray, or solid?

The dose or amount of chemical 

  • How much of the chemical was the person exposed to?

The duration of exposure

  • For how long was the person exposed to the chemical?

The frequency of exposure

  • How often was the person exposed to the chemical?

What are the health effects of exposure to chemicals?

When someone is exposed to a chemical, there are many different health effects that may occur. You’ve likely heard of the medical names given to some of these chemicals and their effects on the body, but what do these terms actually mean? Let’s take a closer look at a few of the most common ones.

Acute toxicity

This refers to the negative reactions in the body that can occur following a single short dose of a harmful chemical or from multiple doses over a 24-hour period. For example, accidental ingestion of a pesticide or insecticide.


A carcinogen is a substance that causes cancer. Unlike many other adverse health effects, carcinogenic effects may take a long time to develop. Asbestos fibres, for example, are carcinogens. 

Asbestos fibres are an example of a carcinogen.
Asbestos fibres are an example of a carcinogen. 

Chronic toxicity

As opposed to acute toxicity, which occurs from a term term exposure, chronic toxicity is an adverse health effect that occurs following repeated or continuous exposure to a harmful chemical. This could have occurred over a relatively short period of time such as a month, or a longer period of time, for example many years. 


If corrosive chemicals come into contact with skin, they will dissolve flesh and cause chemical burns. If they come into contact with eyes, they can damage the corneas and potentially cause blindness. Many acids fall into this category, including hydrochloric acid.


Mutagenic substances are those that can cause DNA to change (mutate). Often mutagenic substances cause irreversible and heritable damage. Mutagens that cause (or promote) cancer are called carcinogens. Examples of mutagens include radioactive substances, x-rays and sun rays (UV).

Reproductive toxin (reprotoxins)

Reprotoxins are substances that interfere with normal reproduction in both men and women. They affect the reproductive organs and/or the endocrine system. Teratogens are reprotoxins that cause birth defects. Examples of teratogens include thalidomide, lead, tobacco and mercury.  

Mercury can cause birth defects.
Mercury can cause birth defects.


Substances that are classified as CMR are carcinogenic, mutagenic or reprotoxic. The use of CMR substances in cosmetic products is generally prohibited, apart from certain exceptions. 

Looking for more information on the safe storage, handling and disposal of chemicals?

If you have any questions about whether your chemicals belong to any of these categories, or if you would like to learn more about the safe handling of hazardous substances, please contact the Chemwatch team today. Our expert staff have many years of experience in the chemical industry and will help you to stay safe and comply with the latest Health and Safety regulations.