Anyone who handles or works with hazardous and non-hazardous chemicals is always at risk of being exposed to them via different routes of exposure. The routes of exposure could be via skin and eye contact or inhalation, or swallowing. While exposure may be harmless, in many cases, exposure may result in severe health effects or, worst case, death.
This article will try to explain what makes chemicals and exposure to chemicals harmful and what health effects are associated with the harmful exposure to chemicals.
So, what makes chemical exposure harmful?
First, it’s important to note that hazard is not the same as risk. Chemicals may be hazardous, but that does not mean a high risk for them to cause adverse health effects. Several factors can point out if the chemical will affect you or your personnel negatively during handling:
Chemical’s nature– first, we need to know how the chemical is classified, whether it is considered carcinogenic or toxic, generally recognised as safe (GRAS) to use, etc. What is its form (liquid, powder, spray, etc.)?
Dose– the dose makes the poison. Everything is poison, given a high enough dose or amount. That is why it is essential to know the quantity of the chemical that the person or persons were exposed to.
Exposure duration– besides dose, in many cases, exposure duration can also impact how severe the negative health effects will be. Generally, the longer the exposure, the higher the risk and the more severe adverse health effects.
Exposure frequency– it’s important to distinguish between exposure duration and frequency. Exposure duration generally refers to the daily exposure, exposure during the work hours in one day. Exposure frequency refers to how often the chemical is used. How many times per week, month or year. This is vital information when handling chemicals that can cause chronic or delayed effects.
So now we know what determines chemical exposure, but what are the negative health effects of exposure to chemicals?
When exposed to any chemical, people need to be aware of many different adverse health effects. That’s why it is important to have and read documents like Safety Data Sheets (SDS) which can give you input on how dangerous or hazardous the chemical you are handling it and what precautions you need to take to reduce the risk of exposure. As mentioned previously, exposure to hazardous chemicals can harm human health or the environment, can cause different illnesses, injuries or, in the worst-case, lead to death. The severity of these health effects defers, and we will mention some of the most dangerous ones here:
The acute toxicity effect of chemicals can manifest as an adverse reaction in the body after a single and short exposure to a small amount of the hazardous chemical or multiple exposures during the 24-hour period. To be described as acute toxicity, the adverse effects need to occur within 14 days of the exposure. Acute effects can be reversible or irreversible depending on the dosages administered, in other words, how toxic or poisonous the chemical is.
Unlike acute toxicity, which occurs from short-term exposure, chronic toxicity adverse health effects occur after repeated or continuous exposure to a hazardous chemical. Even though the effects do not occur immediately, sometimes the negative health effects can occur over a relatively short period, such as a month. Alternatively, the adverse health effects can also only happen after a more extended period, for example, many years.
Strong acids, such as sulfuric acid, and alkali (bases), such as sodium hydroxide, have corrosive properties. When corrosive chemicals contact skin, they will dissolve flesh and cause chemical burns. Similarly, if they come into contact with the eyes, corrosive chemicals will damage the cornea and can potentially cause blindness.
Some of the most dangerous chemicals to handle can cause carcinogenic effects. Substances that can cause cancer are called carcinogens. Heavy metals such as lead, cadmium, chromium, nickel and their compounds have carcinogenic properties. Carcinogenic effects may take a long time to develop or could be delayed.
Substances that have a mutagenic effect are called mutagens. These substances cause the DNA to change, in other words, mutate. These substances often cause irreversible damage to victims. Sometimes these effects can be heritable as well. It is not uncommon for mutagens to promote or cause cancer, in which case they would also be called carcinogens. Some of the most commonly used chemical mutagens are alkylating agents such as ethyl methanesulfonate and N-methyl-N-nitrosourea that induce point mutations in DNA.
Substances that manifest the reproductive toxicity effects are called reprotoxins (reproductive toxicants). Reprotoxins affect the reproductive organs and/or endocrine system in both men and women. Subdivision of reprotoxins called teratogens, cause birth and child defects. Bisphenol A (BPA) is an example of an endocrine disruptor that negatively affects reproductive development. Some other examples include heavy metals such as lead and mercury.
CMR substance is a common term used for substances that are classified as carcinogenic, mutagenic or reprotoxic. These substances generally tend to be prohibited or restricted in many industries and regulations. For example, EU cosmetics legislation contains provisions on CMR substances in cosmetic products. The use of CMR substances is prohibited, apart from in exceptional cases.
As we could see above, the adverse health effects caused by exposure to chemical products can have severe or long-lasting consequences for the exposed person, in the worst case even be lethal. Because of that, it is extremely important to implement risk reduction measures so that the exposure can be minimal, to protect the health and safety of the personnel handling the chemicals. Exposure reduction is usually made by implementing different engineering control measures, such as using exhaust systems and personal protective equipment (PPE) at the workplace. Information on the recommended precautionary and emergency measures can usually be found in the SDS for the chemical in question.