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Chronic Health Effect


A chronic health effect is an adverse health effect resulting from long-term exposure to a substance. The effects could be a skin rash, bronchitis, cancer or any other medical condition.

The term is also applied to a persistent (months, years or permanent) adverse health effect resulting from a short-term (acute) exposure. For example, for most people exposure to the virus that causes COVID-19 causes short-term illness, however some patients experience a lingering chronic condition lasting months or years that is called "long COVID".

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Additional Info

It may take months or years for a chronic health effect to become apparent. For example, inhaling low concentrations of benzene over long periods of time may lead to liver cancer. Likewise, chemical sensitization from exposure to low levels of formaldehyde may have a slow onset.

Another example is cigarette smoking. A smoker may take months or years to realize that their lung capacity is diminished, skin tone is decreased, or circulatory function is inhibited. The onset of these kinds of symptoms is so slow that it can be difficult to realize that one is suffering from adverse health consequences.

Of course, one has to keep chemical exposure and risk in perspective. A brief one-time (acute) exposure to a high concentration of benzene is incredibly unlikely to cause cancer or other lasting health effects. On the other hand, an acute exposure to a high concentration of formaldehyde carries an appreciable risk of causing long-lasting (chronic) health effect called chemical hypersensitivity.

Therefore, it is critical that you not only understand the hazards of workplace chemicals in terms of acute and chronic health effects, but the relative *risks* associated with such exposures. Remember, hazard and risk are two separate concepts. Hazards are inherent in a material regardless of the quantity. Risk is a measure of the likelihood of a hazard to cause harm. For example, gasoline has a significant flammability hazard. However, 3 drops of gasoline poses little risk whereas 10,000 gallons poses substantial risk, particularly if strict safety measures are not followed.

SDS Relevance

Both acute and chronic health effects will be listed in Section 11 (toxicological information) of a Safety Data Sheet. The sheet will explain how you can protect yourself from these hazards and reduce your risk in Section 8 (exposure controls/personal protection).

Chronic effects from long-term exposure to chemicals are fairly common. Recognize the PEL (permissible exposure level) for each substance in your workplace and minimize your exposure whenever possible.

Remember, the preferred methods for reducing chemical exposure, in order of general effectiveness, are:

  1. Substitution of less hazardous materials or processes.
  2. Engineering controls such as fume hoods or other ventilation.
  3. Administrative controls.
  4. Personal protective equipment (PPE).

As the name implies, Personal Protective Equipment protects only the individual person, not others in your workplace. PPE should always be your last line in a multi-layered defense to prevent chemical exposure.

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Further Reading

See also: acute toxicity, carcinogen, emphysema, lethargy, myalgia.

Additional definitions from Google and OneLook.

Entry last updated: Sunday, July 3, 2022. This page is copyright 2000-2024 by ILPI. Unauthorized duplication or posting on other web sites is expressly prohibited. Send suggestions, comments, and new entry desires (include the URL if applicable) to us by email.

Disclaimer: The information contained herein is believed to be true and accurate, however ILPI makes no guarantees concerning the veracity of any statement. Use of any information on this page is at the reader's own risk. ILPI strongly encourages the reader to consult the appropriate local, state and federal agencies concerning the matters discussed herein.