At Cryostar Industries, we’ve provided laboratory equipment repairs and rentals to the New York, New Jersey and Connecticut area for years. We’ve always placed a high priority on service and efficiency. However, we also place the very highest value on lab safety.

Many scientific work environments can be dangerous. Therefore, everyone who enters any kind of lab should be familiar with lab safety. One of the best ways to avoid accident or injury is to know the safety symbols on display.

Knowledge of common lab safety symbols and understanding their meaning is critical to lab operations, daily safety and even cost-efficiency. Labs can house volatile chemicals, flammable materials, hazardous instruments and contaminated specimens. In this article, we’ve created a guide for you to understand each of the most common safety symbols. We break down precisely what they mean plus how to stay safe and eco-friendly.

1. General Warning

This is the most popular safety symbol on display in labs around the world. The “General Warning” symbol is essentially a broad way to notify personnel of potential hazards in the area. It’s usually posted on doors, walls, cupboards and doorways.

Whenever you see this symbol, consider it a reminder to work cautiously. Pay special attention to your surroundings and act accordingly.

2. Biohazard

The “Biohazard” sign is an indication that the lab and instruments you’re working with have had contact with biohazard specimens. Therefore, there’s a risk of contamination. Lab biosafety levels will also be in place to indicate the level of risk associated with the lab.

Make sure you’re always wearing the appropriate personal protective equipment (PPE). Depending on the lab’s biosafety level, this can include gloves, goggles, or even a full protective suit. Always be sure to clean, disinfect and decontaminate the instruments. Also, make sure there are specific rules in place to prevent contamination and keep workers safe.

3. Explosive Materials

This symbol should definitely be taken seriously. The “Explosive Materials” sign indicates that there are chemicals or other agents with explosive properties in the lab. In addition, this may include dangerous chemical reactions from unstable explosives.

Safety policies should be memorized by all lab personnel. Keep your lab equipment calibrated as often as possible. Also, be sure to have policies specific to fire and explosion safety. All chemicals should be stored in designated, safe and secure places.

4. Flammable Materials

This sign can be seen on display in many labs around the country. Whenever this symbol is visible, it means that there are flammable materials present.

Be sure that all flammable materials are stored in a temperature-controlled location. In addition, check that they are properly labeled. Common flammable materials in lab workspaces are solvents or even cleaning materials with harsher or more abrasive ingredients. Keep all of these substances away from extreme heat, open flame or any other agent that may cause them to ignite.

5. Toxic Materials

This is a very popular symbol. You can also find it in most garages or workshops around the country. Whenever you see this symbol, it means that nearby you’ll find toxic, lethal substances. They can harm you if ingested, inhaled, or even if they make direct contact with your skin.

The harmful effects of each agent vary depending on what it is. It also depends where it makes contact and its concentration. Naturally, you should always have the appropriate gear within reach when handling these substances. Whether it’s gloves, goggles or respirators, staff should always have the necessary PPE and have safety protocol memorized.

6. Non-Ionizing Radiation

Whenever you find this symbol on display, it’s an indication that non-ionizing radiation is present in the lab. Essentially, this includes ultraviolet light, infrared, microwave, and radio frequency.

If any of these apply to your lab, be sure to have all sources properly marked. Biological safety cabinets, PPE and environmental controls can limit exposure.

7. Low Temperature

This sign symbolizes extreme low temperatures or cryogenic hazards. Specific equipment, like ultra-low temperature freezers, is well below freezing point. This kind of equipment employs liquid nitrogen to reach their low temperatures.

When it comes to these agents, personal protective equipment is a must. Wear thick rubber gloves that extend to the elbows, closed-toe footwear, rubber aprons and face shields.


When it comes to laboratory safety, you can never be too educated or prepared. At Cryostar, we place a high priority not just on efficiency, but safety.

These are not all of the laboratory safety symbols. However, these are the most essential. Also, they’re the symbols you will most likely come across while working in any scientific environment.

Close-up of a scientist in protective suit with hazardous blue chemical in flask at the laboratory

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