Did you know chemical burns to the eye result in an average of 36,000 ER visits a year in the United States? Chemical eye burns are true emergencies. These kinds of burns can occur at home and at work and can lead to corneal scarring, glaucoma, eyelid injuries, dry eyes, decreased vision, and vision loss.
Any age group is at risk for chemical eye burns if proper precautions are not taken. At home, these injuries occur most commonly in younger children, aged 1–2 years. At work, chemical splashes to the eye(s) occur more commonly in men than women, and more often younger men, ages 20–40. Men are found to be at higher risk because they are more often employed in industries such as construction, industrial chemical manufacturing, mining, agriculture, automotive repair, and other industries in which there is a higher risk for chemical exposure.
What are Acidic and Basic (Alkaline) Chemicals?
Before we dive into specific chemicals that can cause eye injuries, let’s briefly look at two major classifications of chemicals: acids and bases (alkalis).
In chemistry, the intensity of a substance’s acid quality is identified using a measure called the “pH scale.” The pH scale rates substances with a range from 0 to 14. Substances with a rating of 7 are described as neutral. Pure water is neutral. Substances with a number lower than 7 are considered acidic. The lower the number, the more acidic the substance. For example, vinegar has a pH of 2. Substances with a number higher than 7 are the opposite of acidic and called “basic” or “alkaline.” The higher the number, the more basic the substance. For example, ammonia has a pH of 11.
Why are acid and base important when talking about chemical burns? They’re important because both acidic and basic chemicals can cause eye burns; however, as we will see below, basic chemicals often cause devastating burns more rapidly than acidic chemicals, meaning that anyone who is splashed in the eyes with a basic chemical must take action very quickly in order to save their eyes from serious damage.
Eye Burns from Acidic Chemicals
Acid burns usually occur from chemicals with a pH of 4 or less. Most acidic burns typically cause less damage than basic burns because acids don’t penetrate through the eye as easily as bases do.
Examples of potentially harmful acidic chemicals include:
- Hydrochloric acid—found in chemical laboratories and swimming pool cleaners.
- Sulfuric acid—found in battery acids and industrial cleaners.
- Acetic acid—found in vinegar.
- Hydrofluoric acid—found in antirust materials.
Eye Burns from Basic Chemicals
Basic chemical burns occur from exposure to chemicals with higher pH values, usually a pH of 10 or more. Basic substances enter the eye faster than acids. Damage can occur within seconds to minutes following exposure. Burns from basic substances can lead to more complications. Without immediately irrigating the eye (see the section on treatment, below) and seeking medical attention, burns from basic substances can be debilitating. Significant damage can occur each minute that passes without treatment.
Examples of potentially harmful basic chemicals include:
- Ammonium hydroxide—found in fertilizers and household cleaning products.
- Lye—found in drain cleaners.
- Lime—found in cement and plaster.
- Magnesium hydroxide—found in sparklers and fireworks.
- Sodium hypochlorite—found in chlorine bleach.
The most important treatment of any chemical eye splash is to immediately irrigate—flush out—the affected eye(s) with water or an eyewash. To save precious time and eyesight, irrigation should be done immediately at the nearest location. If an eyewash station is available at work, begin eye irrigation at an eyewash station. If an eyewash station is not available begin eye irrigation at a sink or emergency shower immediately. If you are at home, irrigate the eye(s) immediately using a shower. If eyewash and showers are not available or easily accessible, running water from hoses or faucets can be used. The eye(s) should be irrigated for 20–30 minutes before seeing an eye doctor or going to an emergency room. It is important to wash and dilute as much of the chemical as possible right away to prevent worsening or permanent damage of the eye.
One exception to the irrigation rule is that a few chemicals, such as dry lime, react with water and cause strong chemical reactions that can damage eyes further. If you work with chemicals, be familiar with appropriate emergency first aid steps for each chemical in case of exposure.
Chemical eye burns require a comprehensive ophthalmic evaluation as soon as possible to evaluate the degree of the burn and to develop a treatment plan.
Wear proper eye protection and have a prevention plan in place to avoid injuries from chemical splashes. At home, keep all household cleaners in a secure place that is inaccessible to young children. If you are handling chemicals at home, it is important to wear protective eyewear to guard against splashes and to follow the chemical manufacturer’s instructions for usage.
In the workplace, employers should develop procedures and job safety analyses to include the use of safety goggles, face shields, and engineering controls to prevent eye injuries from chemicals. You can learn about the features and protective qualities of different kinds of goggles and face shields by using OSHA’s Eye and Face Protection eTool. Employees should receive ongoing education on the use of personal protective equipment and know the location of emergency eyewash stations at their worksite.
Houman D. Hemmati, Kathryn A. Colby, “Treating Acute Chemical Injuries of the Cornea,” American Academy of Ophthalmology, October 2012.
Joshua J Solano, “Ocular Burns and Chemical Injuries,” Medscape, updated June 14, 2019.
Parul Singh, Manoj Tyagi, Yogesh Kumar, K. K. Gupta, P. D. Sharma, “Ocular chemical injuries and their management,” Oman Journal of Ophthalmology 6, no. 2 (2013).
R. Sterling Haring, Isaac D. Sheffield, Roomasa Channa, et al., ” Epidemiologic Trends of Chemical Ocular Burns in the United States,” JAMA Ophthalmology 134, no. 10 (2016).
Richard Mangan, “Quickly Douse Chemical Burns,” Review of Optometry, February 15, 2015.
Sangeeta Kaushik, Steven Bird, “Topical chemical burns: Initial assessment and management,” UpToDate, updated January 28, 2020