It’s all too easy to forget how many common lab chemicals are dangerous. To remind you, I previously pulled together a list (and a few cautionary tales) of hazardous yet ubiquitous chemicals. It proved popular, so I’ve furthered my efforts to bring you even more chemicals that you should not be messing with, in the lab.
Enjoy, and be safe out there!
10 More Dangerous Laboratory Chemicals and What You Need to Know
1. Benzene
This flammable, lipophilic solvent irritates the skin, lungs, and eyes. Even worse, benzene easily crosses the skin and enters the bloodstream. The body then converts it to toxic metabolites which can damage the brain and heart, suppress the immune system, and even cause leukemia!
2. Ethanol
This ubiquitous solvent and disinfectant is readily absorbed through the lungs and gastrointestinal tract (as many of us already know!). In addition to depressing the central nervous system, ethanol poses a risk because it is so flammable, as one researcher carelessly sterilized equipment with ethanol and a flame discovered.
3. Imidazole
While protein biochemists are likely familiar with imidazole’s use in protein purification, they may not know that imidazole is very corrosive. It can severely burn the skin and eyes, and harm mucous membranes if inhaled!
4. Liquid Nitrogen
As a cryogenic liquid, liquid nitrogen can cause terrible freezer burns and tissue damage. Furthermore, it poses a suffocation risk when the liquid warms enough to become a gas: the gas expands rapidly, displacing oxygen from the air and potentially leading to suffocation in unventilated quarters. This rapid gaseous expansion can also cause explosions in improperly sealed dewars, as a lab at Texas A&M University discovered.
For more information, read our article on liquid nitrogen safety.
5. Osmium Tetroxide
This tissue fixative also acts as an oxidizer with toxic vapors which are especially damaging to the lungs and eyes. Even at low concentrations, its vapors cause tearing, a gritty sensation, and the disturbing (but psychedelic) effect of perceiving rings around bright lights.
6. Phenol
This flammable disinfectant should definitely be used in the fume hood (and not just because it has a sickly sweet smell!). Phenol can corrode the skin and also damage the lungs when inhaled. A high concentration of it can even cause cardiac arrhythmia by blocking cardiac sodium channels.
7. Picric Acid
Commonly used in tissue fixatives, picric acid can stain hair yellow and irritate the eyes and skin. Repeated exposure causes progressively worse dermatitis. Even worse, it damages the liver and kidneys. As if its toxicity wasn’t enough, picric acid corrodes metals and, improperly stored, can crystallize out of solution—leading to an explosion risk!
8. Sodium Dodecyl (Lauryl) Sulfate
As an anionic surfactant, SDS is used at low concentrations in cosmetics and kinds of toothpaste. Scientists will likely be familiar with SDS as one of the components in protein gels. Although SDS has very low toxicity, it can be corrosive and damaging to the skin, especially at concentrations greater than 10%.
9. Sulfuric Acid
This hygroscopic acid corrodes the skin and eyes via coagulating necrosis. To make matters worse, it releases heat when mixed with alcohol or water—meaning that people splashed with sulfuric acid may also suffer from thermal as well as acid burns. Unlike alkaline burns, sulfuric acid effectively forms a scab of coagulum, which restricts further penetration into the exposed tissue. Wear your butyl rubber gloves when working with concentrated sulfuric acid! Latex will not protect you, as one unfortunate researcher discovered.
10. Xylene
Unlike other organic solvents, xylene doesn’t easily cross the skin. However, it can dry and irritate the eyes, mucous membranes, and skin. Xylene does readily enter the body when inhaled: once inside, it intercalates into neuronal cell membranes and changes nerve impulse transmission. This anesthetic effect especially perturbs the cerebellum and motor coordination.
I hope this list has refreshed you on dangerous laboratory chemicals—as well as why you should work in the fume hood and understand the common lab safety signs!
Are you paranoid about poisoning yourself and your lab buddies, or just want an easy summary of safety data sheets? Download our free hazard diamond poster and pin it up in your lab.
Further Reading
- Ashbrook PC, Houts TA. Picric acid. Chem Health Safety 2003;10(2):27
- Final report on the safety assessment of sodium lauryl sulfate and ammonium lauryl sulfate. Int J Toxicol. 1983;2(7):127-181
- Luttrell WE and Conley NL. Toxic tips: Benzene. Chem Health Safety 2011;18(4):32-33
- Luttrell WE. Toxic tips: Sulfuric acid. Chem Health Safety 2003;10(1):40-41
- Luttrell WE. Toxic tips: Xylene. Chem Health Safety 2012;19(2):34-35. 34-35
- National Institute for Occupational Safety and Health. Osmium tetroxide. (Accessed: 20 October 2021)
- National Institute for Occupational Safety and Health. Picric acid. (Accessed: 20 October 2021)
- PubChem. Benzene – Compound Summary. (Accessed: 20 October 2021)
- PubChem. Ethanol – Compound Summary. (Accessed: 20 October 2021)
- PubChem. Osmium Tetroxide – Compound Summary. (Accessed: 20 October 2021)
- Sigma-Aldrich. Material Safety Data Sheet: Imidazole. (Accessed: 20 October 2021)
- Walters D. Lesser known hazards in histopathology laboratories. Chem Health Safety 2001;8(6):28
Originally published June 2013. Reviewed and updated November 2021.
