Every workplace contains some kinds of chemical – from basic cleaners, to industrial chemicals used in manufacturing. Many chemicals can be extremely hazardous to the eyes, causing temporary vision loss or even blindness. Eye safety is a key way to mitigate the chemical risks workplace cleaners can have on your eyes.
Chemicals are defined by their acidity or alkalinity, also know as the PH of a chemical. This is measured on a scale from 1 through 14, with 7 being the middle, indicating a neutral chemical (e.g. pure water), acids indicated below 7, and alkali above 7. Interestingly, the scale is actually logarithmic, meaning a 6.0 is 10 times more acidic than water, and a 5.0 is 100 more acidic.
Acid and alkaline chemicals are both considered to be corrosives, meaning they can attack and chemically destroy exposed body tissue, immediately upon contact.
- Alkali burns (PH over 7) – These are usually the most dangerous kinds of corrosive chemicals, and the most common alkali substances are ammonia, lye, potassium hydroxide, magnesium and lime. The strongest ones are sodium/potassium hydroxide (often used as drain cleaners). These penetrate the eye more severely, and can damage not only the external cornea, but also the lens of the eye. Glutaraldehyde is another harsh alkali, common in medical sterilization, but also found in leather tanning and fracking fluid.
- Acid burns (PH under 7)– These generally do not penetrate the eye as severely, (with the exception of hydrofluoric acid, which is a dangerous as an alkali burn) and generally only penetrate the very front of the eye. Examples include sulfuric acid (battery acid or drain cleaner), hydrochloric acid (swimming pool cleaner), acetic acid (vinegar) and hydrofluoric acid (glass etching). Common substance examples are vinegar, glass polish, battery acid, swimming pool cleaners, silverware cleaners, glass etching, rust removal.
Even chemically neutral chemicals, such as pepper spray and detergent, can be irritating to eyes, though they do not tend to cause the level of damage of alkalis and acids. Remember, any foreign substance, chemical or otherwise, can cause damage, and CSA approved eyewear should be worn in any workplace that may risk exposure.
For a list of chemicals and where they are commonly found, click here.
Remember, be “eye safe”!