Lab Safety Pictograms and Their Meanings, Part 1

Written communication started with pictures. From Egyptian hieroglyphics to Native American petroglyphs, humans began communicating with simple visual images. While we’ve come a long way since then (as evidenced by how easily you can read this article), sometimes pictograms still give us information. This is especially true with lab safety, where lab techs want to quickly and clearly communicate information about hazardous conditions without the need for translation.

Clearing Up Any Confusion

While we naturally focus much of our lab safety concerns on the proper use of dedicated lab furniture, we know that a picture can often best convey the essence of a safety concern, but not always the underlying details. In this first of two posts, we explain (in the language we know best) the meaning behind some of the modern hazard communication standards set by OSHA.

Health Hazard

While stars are often bright and beautiful, the star on this pictogram is clearly damaging to the human it has invaded. This pictogram indicates that the materials within this labeled container are chemicals that can have a serious, sometimes long-lasting impact on the health of anyone who comes in contact with them. There are many types of harmful reactions that can occur in the human body through these hazards. They can cause cancer, respiratory issues, reproductive complications, dangerous mutations in human tissue, or adversely impact specific organs in the body.


Even our earliest ancestors would recognize this symbol. While flames are useful in everything from keeping us warm to supporting chemical reactions in your lab, flammable and combustible materials also present a lab safety hazard. Materials labeled with this symbol will easily ignite and burn in air and some of them will self-heat. Substances covered by this pictogram take many forms, including liquids and solids as well as gases and aerosols. All such materials must be kept far not only from open flames and heat, but also sparks and other potential ignition sources.

General Warning

This exclamation point is more nuanced, referring to general lab safety warnings that aren’t covered in more specific categories. This cautionary pictogram reminds lab workers that safety issues can arise anywhere in your lab. This sign might appear on a doorway, leading into a work area that contains particularly hazardous processes. It might also be found on a cabinet that hangs particularly low over the work surface of some dedicated lab furniture. There could be a multitude of meanings for this pictogram, so the basic message is to be cautious and pay attention. Check with someone if you aren’t certain about safety procedures, or the proper handling of specific equipment or substances.

Compressed Gas

The first high-pressure gas cylinders were crafted in the 1880s, so this is a pictogram that any modern lab technician would recognize. Three types of compressed gases are commonly used in labs: liquefied gases (which become liquid at room temperature when compressed), non-liquefied gases (which retain their gaseous state at room temperature when compressed), and dissolved gases (gaseous reservoir hydrocarbons which have been dissolved in liquid reservoir hydrocarbons). It is the pressure under which these gases are stored that makes them hazardous, creating the possibility for explosions, fire, or injury from a fast-moving emission from the cylinder.


Corrosive materials are substances that can eat away at everything from human skin to metal instruments and the work surfaces of your dedicated lab furniture. The keys to safe storage of corrosive substances include maintaining them at proper temperature and humidity. The keys to safe usage of these materials is the use of proper protection, including goggles, gloves, and other protective gear.

Pictograms are increasingly common in our multicultural world. It’s always helpful to be reminded of their meanings. It’s also always helpful to make a lab safety investment in dedicated lab furniture. Our IonBenches use a specially designed laminate that can withstand many potential lab accidents that could be caused by these corrosive or flammable materials we’ve just discussed.

To learn more about how our lab benches are dedicated to your safety, contact Tim Hawkins via email or at 1-888-669-1233. Also stay tuned for the second in our series on lab safety pictograms in our next post.