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Responding to Chemical Spills

The science teacher must be prepared to clean up minor spills that may occur in the lab and know how to proceed in the event of a major spill. A proper response could prevent major disruptions to science laboratory operations, damage to laboratory equipment, and serious bodily harm. If a spill is serious, students may be required to evacuate the lab, and spills could discharge into the atmosphere, sewer system, and surrounding soil or surface water. If handled properly, however, a chemical spill can be nothing more than a nuisance.

Causes of chemical spills

There are a number of factors that can result in chemical spills in science labs, including:

• overfilling of waste containers;
• storing hazardous chemicals in inappropriate locations (e.g., in cabinets or counter tops);
• storing chemicals that have deteriorated over time (e.g., peroxides becoming explosive);
• mixing incompatible waste or containers in the lab or prep room;
• inappropriately labeled containers;
• people not paying attention to what they are doing;
• chemicals inadvertently dropped on the floor or counter top; and
• inappropriate or incomplete cleanup.

Assessing the situation

When preparing for chemical spills, determine the hazard class of all the chemicals to be used during laboratory work. Of most concern are chemicals that are flammable, corrosive, toxic, and reactive to air or water.

If a chemical spill occurs, don’t panic. First, have staff and students move far away from the area while you assess the situation and determine the appropriate response. Try to determine the identity of the spilled substance using the Safety Data Sheet (SDS)—specifically, sections II (Hazard Identification), IV (First Aid Measures), V (Fire-Fighting Measure), VI (Accidental Release Measures), and VIII (Exposure Control/Personal Protection). When evaluating the chemical spill, consider:

  • the spill hazards and resulting risks (e.g., volatile vapors, flammable, toxic, water or air reactive, ignition sources, oxidizers).
  • the chemical volume in the spill (i.e., simple or complex spill).
  • the potential impact of the spill (e.g., toxic vapors after cleaning, damage of the equipment).
  • the severity of the spill (i.e., major vs. minor spill).
  • the appropriate personal protective equipment such as eye protection, protective gloves, and lab coat or apron.

Minor spills vs. major spills

Minor spills can be handled by the science teacher in a safer manner. A spill kit can be used to clean up minor spills. Spill kits can be purchased from commercial chemical supply companies such as Flinn Scientific (see Resources for information about the contents of spill kits). To address a minor spill:

• immediately alert lab occupants and evacuate the area, if necessary.
• close the lab door and increase ventilation through fume hoods. Windows should be opened.
• don personal protective equipment, as appropriate to the hazards.
• try to control the spread of the liquid.
• place a dike from the spill kit around the outside edges of the spill.
• use absorbent materials such as vermiculite, cat litter, or spill pillows.
• prevent the spread of dust and vapors.
• immediately remove contaminated clothing and flush the skin with water for no less than 15 minutes.
• protect floor drains for environmental release by covering them up or placing a protective dike around them.
• distribute loose spill control materials, such as kitty litter and sand, over the entire spill area, working from the outside in.
• use brush and scoop to place materials in an appropriate container.
• place a hazardous waste sticker, identifying the material as Spill Debris involving the chemical, onto the container.
• decontaminate the lab using a mild detergent and water.
• notify chief building administrator, science supervisor, and chemical hygiene officer.
• complete an accident report, if required.

The science teacher will not be able to handle major spills. During a major spill, a fire or chemical reaction is ongoing, medical attention could be required if a lab occupant experiences a physical injury, and the spill contains dangerous or unknown chemical components. To address a major spill:

• immediately notify students and other occupants in the lab.
• immediately evacuate the site, if necessary.
• shut off gas, fume hood, and other equipment, if possible.
• activate the fire alarm.
• secure medical assistance, if necessary (e.g., school nurse).
• consult with first responders (e.g., fire, police).
• try to assess what caused the spill.
• notify chief building administrator/science supervisor and Chemical Hygiene Officer.
• complete an accident report.

Responding to safety issues with chemicals

If chemicals touch the skin or clothing:

• immediately flush skin with water for no less than 15 minutes (eyewash/shower).
• quickly remove all contaminated clothing or jewelry while rinsing.
• use caution when removing pullover shirts or sweaters to prevent contamination of the eyes.
• check the SDS to determine if chemicals have delayed effects.
• discard contaminated clothing or launder them separately from other clothing. Leather garments or accessories cannot be decontaminated and should be discarded.
• do not use solvents to wash skin.
• (for flammable solids on skin) brush off as much of the solid as possible, then proceed as described above.
• fill out an accident report.

If chemicals get into the eyes:

• immediately flush eye(s) with water for at least 15 minutes using an eyewash station. Hold the eyes open to wash, and the eyeballs must be rotated to rinse the surface area. If an eyewash station is not available, pour water on the eye, rinsing from the nose outward, to avoid contamination of the unaffected eye.
• remove contact lenses while rinsing.
• seek medical attention regardless of the severity. Explain carefully what chemicals were involved. If easily accessible, bring an SDS.
• fill out an accident report.

If chemicals are inhaled:

• close containers, open windows, or otherwise increase ventilation, and move to fresh air.
• seek medical attention if symptoms such as headaches, nose or throat irritation, dizziness, or drowsiness persist. Explain carefully what chemicals were involved.
• review the SDS to determine how the chemicals affect your health, including delayed effects.
• fill out an accident report.

If chemicals are accidentally ingested:

• contact the school nurse.
• immediately call the Poison Control Center at 800-222-1222 for expert advice.
• do not induce vomiting unless directed to do so by the school nurse or Poison Control Center personnel.

In the end

Anyone involved in the cleanup must be supplied appropriate personal protective equipment (PPE) before addressing the spill. The teacher overseeing the spill has must be sure to provide appropriate PPE to avoid legal trouble under Duty of Care expectations should someone get injured during the spill.

To help prevent and prepare for future chemical spills, all chemical hazard incidents should be investigated and reviewed by chemical hygiene officer/safety compliance officer. And finally, any employees working in the lab must have safety training, including spill cleanup procedures. It also helps to better protect the science teacher and school from potential litigation.


Guide for Chemical Spill Response Planning in Laboratories—

Chemical spill procedures—

Spill kit contents—

Submit questions regarding safety in K–12 to Ken Roy at, or leave him a comment below. Follow Ken Roy on Twitter: @drroysafersci.

NSTA resources and safety issue papers
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  1. Jay Skarda
    Posted January 18, 2018 at 12:36 pm | Permalink

    This is pretty good information. One of the points that we always have concerns about is the concept of “minor vs major” spills. A large spill of something that is low-hazard is easy to deal with by lab staff. A tiny spill of beta-mercaptoethanol clears out the lab pretty quick. Keep the fume hoods open/running. That will help. Know what is in the lab. Prepare accordingly. A chemical release drill is helpful.

  2. Dr. Ken
    Posted January 18, 2018 at 1:44 pm | Permalink

    Dr. Ken’s response to Jay Skarda

    Jay..thanks..great points on this spill topic. Just one note..teachers should investigate if their ventilation system for the lab is effected totally by the lab fume hoods or a separate ventilation system (e.g. Rooftop unit). Reason being..the fume hood may already be operational and not needing to waste time going around trying to turn on the hoods but to exit the lab. Thanks again..great comments.

    Dr. Ken

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