Headlines in the press:

“Teacher is severely injured opening a bottle of Picric Acid!” “Students exposed to mercury in school science laboratory diagnosed with blood poisoning.” “Several students are blinded by exploding sodium in a high school science demonstration.”

These are all too frequent headlines seen in the press these days. Unfortunately, although the word is now out on the street about hazardous chemicals and action is being taken in schools across the country, there are still pockets of “chemical craziness” where these dangers loom.

To date, there is no one central location where science teachers can secure a list of hazardous chemicals which are at present an unacceptable risk as a part of a high school or middle school science inventory. Other hazardous chemicals require special precautions, storage and handling.


At present, the best resource available for information on hazardous chemicals is the Material Safety Data Sheets or MSDS. They are exceptional sources of information which are required by law for the user of hazardous chemicals to have on site. Required information includes the following list:

  • Company Information
  • Hazardous Ingredients
  • Physical Data
  • Fire and Explosion Hazard Data
  • Health Hazard Data
  • Reactivity (Instability) Data
  • Spill or Leak Procedures
  • Special Protection Information
  • Special Precautions

The Occupational Safety and Heath Administration, or OSHA, specifies the information to be included on an MSDS, but does not prescribe the precise format for an MSDS.


Before decisions are made on the management of science laboratory chemicals, there needs to be knowledge of exactly what is located in the chemical storeroom. This is where the process begins in taking care of the “chemical problem” in science laboratories. An inventory needs to be taken to determine the types and quantities of laboratory chemicals. Use extreme caution in handling chemical containers found in the storeroom, cabinets, and other places. Old chemicals can be unstable and become explosive over time.

Once an inventory is taken, decisions need to be made on which to keep and which to discard. Criteria such as toxicity, carcinogenicity, curriculum requirements, ventilation requirements, cost of disposal, etc. need to be taken into consideration.

Guidelines need to be developed and put in place for purchase, amount, storage, use and disposal of chemicals.


One thing to remember is that school districts own chemicals from cradle (point of purchase) to grave (final resting place). Removal and disposal of hazardous laboratory chemicals can be very expensive. Nationwide, disposal costs for school chemistry laboratory cleanouts have been estimated to cost between $500 to $80,000. Depending on the chemical, disposal can be as simple as pouring it down the drain or as complex as having a professional hazardous waste contractor remove the item. Consult the MSDS on disposal, and be responsible in decision making.


The following is a partial list of hazardous chemicals by category. They have been identified by different federal and state safety-related departments or divisions. They tend to be common chemicals still found in some high schools and even middle schools. All should be removed and disposed of in a legal and environmentally safe way.

A. Explosives (Chemicals which are unstable and capable of rapid and violent energy release):

  1. Ammonium dichromate (NH4)2Cr2O7
  2. Ammonium Nitrate NH4NO3
  3. Benzoyl Peroxide (C6H5CO)2O2
  4. Carbon Disulfide (CS2)
  5. Diisopropyl Ether ((CH3)2CH)2O
  6. Ethyl Ether C4H10O
  7. Formic Acid HCOOH
  8. Picric Acid 2,4,6-(NO2)3C6H2OH
  9. Perchloric Acid HCIO4
  10. Potassium Metal K
  11. Sodium Metal Na
  12. Lithium Metal Li

B. Highly Toxic Materials (Chemicals which can cause severe illness or death when inhaled, absorbed or ingested in small amounts):

  1. Barium Hydroxide
  2. Carbon Tetrachloride
  3. Chlorine
  4. Mercury
  5. Mercuric Chloride
  6. Mercuric Nitrate
  7. Mercuric Oxide
  8. Phosphorous
  9. Potassium Cyanide
  10. Silver Cyanide
  11. Sodium Cyanide

C. Carcinogens (Chemicals causing cancer in mammals):

  1. Arsenic Powder
  2. Asbestos
  3. Benzene
  4. Chromium Powder
  5. Chromium (VI) Oxide
  6. Lead Arsenate

(Probable Carcinogens)

  1. Nickel Powder
  2. Acetamide
  3. Formaldehyde
  4. Lead (II) Acetate
  5. Nichol (II) Acetate

D. Unstable and/or Hazardous Chemicals Recommended for Removal

  1. Beryllium Chloride
  2. Carbon Disulfide
  3. Chromic Acid
  4. Dimethyl Ether
  5. Formaldehyde
  6. Hydrocyanic Acid
  7. Hydrofluoric Acid
  8. Metallic Peroxides of Barium and Calcium
  9. Perchloric Acid
  10. Phenol
  11. Picric Acid
  12. Potassium Cyanide
  13. Sodium Cyanide
  14. White Phosphorous


With all other remaining hazardous chemicals, prudent practice is the way to go. When working with hazardous chemicals, the following should be addressed: appropriate storage, labeling, inventory, ventilation, personal protective equipment, disposal, spills, engineering controls, fume hoods, and safety training programs..

Science can still be fun and safe at the same time. Plan ahead and use your head!



National Clearinghouse for Educational Facilities:

Occupational Safety and Health Administration:

Dr. Ken Roy is Director of Science & Safety for the Glastonbury Public Schools and is an authorized OSHA Instructor, Glastonbury, CT 06033-3099, USA. Fax 860-652-7275
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

I became a member of NSELA to be part of a group that was focused on science education. I stayed as member because I found a group of science educators whose focus was on advancing science education.

Cindy Hopkin, Middle School Science Teacher, Corpus Christi, Texas

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