12 Important Lab Safety Symbols and Their Meanings

When you walk into any type of lab, safety symbols should be present. Although many of the signs and symbols posted may seem redundant or even unnecessary, they are there mainly to prevent accidents. When new to a lab, make sure you familiarize yourself with all of the symbols and understand the meanings behind them.

Pink may be pretty, but also dangerous when it is labeled as a biohazard. According to Auburn University, the biohazard symbol dates back to 1966. It's used internationally to denote a substance or object that presents an infectious hazard to humans. Handling a biohazard requires care and, often, special protection.

The radiation symbol, sometimes called the "radiation trefoil," indicates something that presents a radiation hazard. This means the object or substance emits radiation in excess of what is considered completely safe by the International Atomic Energy Agency. The symbol, which has been in use since 1946, is used internationally.

It's important to know what items in a lab are flammable. In fact, the flames symbol is one of the most recognizable signs you can encounter. In 2015, the flame symbol became part of the Globally Harmonized System of Classifying and Labeling Chemicals, making this the official universal lab symbol for a potential fire hazard.

The skull and crossbones symbol for poison is universal and ancient. According to Princeton University, it has been used in some forms since at least the early 1800s. It too is now part of the Globally Harmonized System of Classifying and Labeling Chemicals, which means it is used worldwide to denote substances or chemicals that are poisonous to humans.

Irritants can be harmful to eyes, skin, or respiratory tract. The old irritant symbol was an "X" sign, but the new version, according to the U.K.'s Health and Safety Executive, is an exclamation point. This symbol can also indicate a substance is hazardous to the ozone layer.

Because fire is a hazard in many labs, it's imperative to properly label fire extinguishers. Oshatraining.com reports that the Occupational Safety and Health Administration (OSHA) only requires that fire extinguishers be clearly "identified" in the lab, and the easiest way to be in compliance is to have a sign with a fire extinguisher symbol.

Look for the "not" symbol to be prominently displayed in the lab when there is something you should not do. Part of the International Standards Organization (ISO) requirements for universally recognizable safety signs, the circle with the line through it means "don't do this." You'll see it with a cigarette for "don't smoke," with a fork and plate for "don't eat," and with a variety of other easy-to-identify symbols for things you can't safely do in the lab.

It's good to know where all of the exits are located, especially when working in a lab environment where you may need to get out quickly. In fact, according to the National Institute of Building Sciences, labs are required to mark exits routes from the area with clearly-identifiable signs. The type of sign may vary depending on the location, but you'll see an exit marked in every lab that is in compliance.

Due to many hazards, some areas are labeled as restricted. LabManager reports there are several reasons a lab may want to use this type of sign or symbol, including patient or company privacy, potential contamination from outside sources, and possible safety hazards to those near the lab.

According to the American National Standards Institute, many labs are required to have an emergency shower. This allows students or workers to rinse off chemicals and other hazards quickly in the event of an emergency. These showers should be clearly labeled with signs and symbols, such as the one above.

Another symbol from the Globally Harmonized System of Classifying and Labeling Chemicals, this sign indicates something that is corrosive to surfaces and damaging to human skin. You may find it on bottles in a chemistry lab or biology lab, among other places.

Some labs have areas where animals are tested or used in work, and these animals are often identified with symbols and signs. According to the University of California San Diego, the federal government requires clear labeling for lab animals. There is no universal symbol for laboratory animals, but signage must be clear.

Reading labels and paying attention to signs is an important part of lab safety, whether you're working in a professional lab or studying in a univerity or school lab. Get to know the meanings behind lab safety symbols so you are informed about the occupational hazards you may encounter.