50 Safety Symbols You’ll See in a Lab (+ Why They’re Important)

Download Article

Fire, hazard, physical, and radiation safety symbols used in labs

Co-authored by Raven Minyard, BA

Last Updated: December 24, 2025 Fact Checked

Download Article

• Fire Safety
|
• Hazard
|
• Physical Safety
|
• Radiation Hazard
|
• Why Safety Symbols Are Important

|Show more |Show less

Laboratory safety symbols are standardized icons used to help lab personnel quickly identify risks such as fire, biological, and radiation hazards. It’s important for anyone who works in a lab to know what these symbols mean. In this article, we’ve compiled a list of 50 common symbols you might run into, including fire safety symbols, hazard symbols, physical safety symbols, and radiation hazard symbols. Keep reading to learn what each symbol represents.

Common Laboratory Safety Symbols

Download Image

Lab safety symbols are universal symbols that help prevent accidents and emergencies in a lab. Some symbols, like flammable material and no open flames, are about fire safety, while others, like biohazard and toxic material, focus on general hazards. Others, like the eyewash station symbol, are for personal safety.

Steps

Section 1 of 5:

Fire Safety Symbols

Download Article

1. 
   1
   Fire Blanket The fire blanket symbol shows a person holding a fire blanket in front of flames. It indicates the location of a fire blanket within the lab. Fire blankets are used to smother fires by cutting off oxygen.
2. 
   2
   Fire Extinguisher The standard fire extinguisher symbol displays a white fire extinguisher icon and flames on a red background. This label is posted by the fire extinguisher so you know exactly where it is in case of an emergency.
   Advertisement
3. 
   3
   Fire Hose This symbol shows a white fire hose on a red background. It indicates the location where a hose with water or any fire retardant is placed. A fire hose may be used to extinguish or control a fire before the fire department arrives.
4. 
   4
   Flammable Material The flammable material symbol consists of a black flame, typically on a yellow, triangular background. This symbol indicates that there are flammable chemicals or materials in the lab and serves as a reminder that flammable materials should be stored away from heat and open flames.

   • Flammable materials are often classified as liquids or solids that may ignite within less than 5 minutes of heat or open flame exposure. They may pose serious health and safety risks if not handled and stored properly.
   • Some flammable materials include ethanol, acetone, and many common household cleaners.
5. 
   5
   No Open Flames This symbol consists of a black flame on a white background. It is crossed out by a red circle with a line drawn through it. This means that no flames are allowed in the lab, including those produced by matches, lighters, Bunsen burners, etc. Labs often display this warning when they contain highly flammable or combustible materials.
6. 
   6
   Oxidizing Material The oxidizing material symbol consists of a flame over a circle, typically on a yellow triangle. This warns that the lab contains chemicals that make other materials burn hotter and faster because they supply additional oxygen. These materials should always be stored away from flammable materials and handled with caution.

   • Oxidizing agents can be hazardous to human health, so always wear proper PPE when handling these materials.
   • Some oxidizing materials include peroxides, bromine, and chlorine.
Advertisement

Section 2 of 5:

Hazard Symbols

Download Article

1. 
   1
   Biohazard The biohazard symbol features a trefoil around a small central circle and is typically displayed on a yellow, triangular background. This symbol denotes a space or full facility that handles biological materials, such as blood samples, infectious agents, bacteria, and other human-derived samples. It reminds staff to take necessary precautions, such as wearing proper PPE and doing regular cleanings. There are 4 biosafety levels.

   • Biosafety Level 1: Organisms that don’t usually cause disease in healthy adults but are capable of causing infections and have a minimal potential hazard to the environment and laboratory personnel.
   • Biosafety Level 2: Organisms capable of causing mild infections and that have moderate potential hazard to the environment and laboratory personnel.
   • Biosafety Level 3: Organisms capable of causing severe infections and spreading via aerosol. They have high individual risk and moderate community risk.
   • Biosafety Level 4: Organisms that have a high potential of causing serious infection to individuals and communities. They have a very high transmission rate and have no available treatment or preventive measures.
2. 
   2
   Carcinogenic Material The carcinogenic material symbol features a symbol that resembles a broken chain inside a yellow triangle. It isn’t used as often as the general health hazard symbol, but it means that a lab contains carcinogenic materials, or materials that can cause cancer by damaging DNA.
3. 
   3
   Corrosive Material Hazard This symbol shows two vials dripping liquid onto a hand and a flat surface. It’s a warning that the lab contains corrosive materials that can eat away and burn the skin, metals, and other materials. It reminds personnel to always wear goggles, gloves, and other PPE, and to be extremely careful when handling the materials.

   • Some corrosive materials include hydrochloric acid, sulfuric acid, and sodium hydroxide.
4. 
   4
   Electric Hazard This symbol depicts a hand being shocked by a wire. It indicates the presence of a device that might give mild to severe electric shock. The high voltage symbol is often used in place of the electric hazard symbol.
5. 
   5
   Explosive Material The explosive material symbol depicts a black bomb exploding on a yellow triangle. This warning is used for labs handling chemicals with explosive properties. These materials may explode if dropped, shaken, mixed with other substances, or exposed to high heat or flame.

   • Many labs don’t handle explosive chemicals, but they do utilize aerosols and compressed gases, which can pose a similar threat.
   • This symbol is often used to mark specialty housing or storage for compressed gas and explosive materials, which are kept away from the central workspace.
6. 
   6
   General Warning The general warning symbol consists of a black exclamation point on a yellow triangular background. As the name suggests, it serves as a general warning of the presence of hazards rather than a specific one. It warns lab personnel of the persistent presence of potential risks and to regularly check PPE and other safety procedures.
7. 
   7
   Glassware Hazard The glassware hazard symbol depicts a shattered vial. This indicates the presence of broken glass or the potential for broken glass, especially if chemicals are involved. Personnel are typically required to wear gloves, goggles, and other PPE to prevent injury.
8. 
   8
   Harmful Irritants The harmful irritants symbol features a black X inside a yellow triangle. It is sometimes used in place of the general warning symbol to indicate the presence of harmful chemicals that cause irritation. These chemicals are not as severe as toxic or poisonous chemicals.
9. 
   9
   Health Hazard The health hazard symbol shows the silhouette of a person with a starburst on the chest. This symbol is displayed in labs that house materials associated with chronic illness or other human health risks. These materials are often classified as carcinogens, mutagens, reproductive toxins, and aspiration toxins.
10. 
    10
    High Voltage This symbol consists of a downward-pointing arrow shaped like a lightning bolt. It warns staff that the lab contains a piece of equipment with enough voltage to seriously injure or kill them. It reminds them to always wear PPE, like rubber gloves, when operating the high-voltage equipment.
11. 
    11
    Hot Surface The hot surface symbol includes a horizontal black line with wave lines emanating from it, like heat waves. This symbol is placed near any hot surface to prevent personnel from burning themselves if they touch it.
12. 
    12
    Laser Beam Hazard This symbol features a sun-like icon with one ray extending to the black trim of the yellow triangular background. It warns that laser beams are present, which can pose a risk to skin, eyes, and flammable materials. It reminds personnel to wear protective clothing at all times when operating or in the presence of lasers.
13. 
    13
    Low Temperature/Cryogenic Hazard This symbol features a black snowflake on a yellow background. It warns that certain chemicals and materials must be stored at temperatures far below that of a conventional freezer. Personnel must use proper PPE when retrieving and handling these materials.

    • Liquid nitrogen is a common example of a cryogenic material.
14. 
    14
    No Light This symbol consists of a lightbulb crossed out by a red circle with a line through it. It means that an area contains light- or photo-sensitive materials that need to be kept in the dark. Any light sources, including flashlights and lighters, are prohibited.
15. 
    15
    Toxic Material/Poison The standard poison symbol is a skull and crossbones. This symbol serves as a general warning of the presence of materials that can cause serious harm if ingested or inhaled. The effects vary depending on the material and degree of exposure. Personnel must wear extensive PPE when handling these materials.

    • Some examples of toxic materials include ammonia, bleach, and battery acid.
16. 
    16
    UV Light The UV light symbol consists of a sun with “UV” written in the center. It is used to mark all areas of a lab in which UV light is being used. While invisible to the naked eye, prolonged exposure to UV rays can cause burns, skin ulcerations, and even certain types of skin cancer.
Advertisement

Section 3 of 5:

Physical Safety Symbols

Download Article

1. 
   1
   Breathing Masks/Respirator Required The standard breathing mask symbol depicts a person wearing a gas mask. This indicates that an area’s oxygen supply has been contaminated and that personnel should wear full-face or half-face respirators to avoid inhaling airborne diseases, toxins, and pollutants.
2. 
   2
   Drinking Water The drinking water symbol shows a glass of water under a running faucet. It indicates that the water from a certain sink or tap is safe to drink, as opposed to water that should not be consumed.
3. 
   3
   Emergency Bell The emergency bell symbol consists of a bell with sound waves emanating from it on a red background. This indicates the location of the bell that should be pressed during an emergency, like a fire or accident. It alerts other personnel of the emergency so they can proceed to safety.
4. 
   4
   Emergency Meeting Station This symbol shows a group of people gathered in the center with 4 arrows pointing at them. It indicates the location of the place all lab personnel should meet during an emergency to stay safe and await further instructions.
5. 
   5
   Eyewash Station The eyewash station symbol shows an eye being sprayed with water with a plus sign beside it. This symbol marks the location of an eyewash station, which is a sink where personnel can flush away chemicals that may have gotten in their eyes. These stations should be used immediately when corrosive or otherwise harmful materials come in contact with someone’s eyes.
6. 
   6
   Face/Safety Mask Required This symbol depicts a person wearing a face mask over their nose and mouth. It means personnel are required to wear a standard face mask to protect them from inhaling dust or germs.
7. 
   7
   Face Shield Required This symbol displays a white face shield on a blue background. It simply means that personnel are required to wear a face shield while working. This protects their face from splashes, sparks, flying debris, and other hazards.
8. 
   8
   First Aid Station The first aid symbol consists of a white plus sign inside a red square, typically with “first aid” written underneath. It marks the location of first aid kits so personnel can easily get the help they need in case of emergency or injury. There are typically multiple first aid stations within a lab or facility.
9. 
   9
   Food and Drink Prohibited This symbol consists of an image of a soda can, sandwich, and cigarette being crossed out by a red circle with a line through it. Many labs contain high concentrations of toxins and harmful materials, so prohibiting food and drink prevents contamination or the accidental ingestion of harmful chemicals.
10. 
    10
    Gloves Required This symbol shows two white gloves on a blue background. It suggests the presence of potentially harmful substances and warns that all personnel need to wear gloves and other PPE to avoid chemical burns, corrosion, allergic reactions, or other issues.
11. 
    11
    Hair Protection Required This symbol depicts a person wearing a hair net or similar covering and means that all personnel are required to cover their hair before working. This prevents hair from contaminating whatever they’re working on and stops hair from getting in machinery.
12. 
    12
    Hand Sanitization Station This symbol depicts a pair of hands lathered with soap. As the name suggests, this symbol is located near an area where lab personnel can clean their hands with hand sanitizer.
13. 
    13
    Hand Wash Station The hand wash station symbol shows a pair of hands under a running faucet. This simply indicates a designated spot where personnel can wash their hands, as proper hygiene is extremely important when working in a lab.
14. 
    14
    Hearing Protection Required The hearing protection required symbol depicts a person wearing headphones or ear muffs, and as the name suggests, means personnel are required to wear hearing protection while working. These signs are found in labs and working environments with dangerously high noise levels.
15. 
    15
    Lab Coat Required This symbol typically depicts a white lab coat on a blue background. As the name suggests, it means personnel are required to wear a lab coat when working in a certain area. Lab coats protect against splashes, spills, biohazards, and chemicals.
16. 
    16
    No Electronics The no electronics symbol typically shows several electronics (like laptops, phones, or cameras) crossed out by a red circle with a line going through it. This means that electronic devices are not allowed within a certain area, either for privacy or safety reasons.
17. 
    17
    No Gloves The no gloves symbol shows a glove crossed out by a red circle with a line through it. This means personnel are not allowed to wear gloves within a certain area. This is typically because the gloves could pose a safety hazard when operating certain machinery.
18. 
    18
    No Open Hair This symbol typically depicts the outline of long hair, crossed out by a red circle with a line through it. It functions similarly to the hair protection required symbol, as it indicates that personnel cannot have their hair down. They typically need to cover it with a hair net or another form of hair covering.
19. 
    19
    No Open Shoes The no open shoes symbol typically depicts a pair of flip-flops or other open-toed shoes being crossed out by a red circle with a line through it. This means that personnel must wear closed-toed shoes when they’re in the lab. Doing so prevents potential injuries.
20. 
    20
    No Pacemakers or Metallic Implants This symbol displays a heart with an electronic pulse generator, crossed out by a red circle with a line through it. Labs with this sign utilize equipment with strong magnetic fields that could cause pacemakers and metallic implants to malfunction or cause severe bodily harm. Even those without pacemakers or implants should remove all metal and jewelry before entering these labs.
21. 
    21
    Protective Clothing Required This symbol typically depicts a white jumpsuit or hazmat suit on a blue background. It means that all personnel must wear full protective clothing when in a certain area. The exact PPE may vary depending on the lab, and it protects against chemical splashes and other hazards.
22. 
    22
    Restricted Entry The restricted entry symbol shows a person standing or walking who is crossed out by a red circle with a line running through it. This means that only authorized personnel are allowed to enter a certain area, usually for safety reasons.
23. 
    23
    Safety Glasses Required This symbol depicts a person wearing safety glasses or goggles. It indicates that personnel must use protective goggles in a certain area. Doing so protects them from potential eye injuries when handling certain chemicals or materials.
24. 
    24
    Safety Shoes Required This symbol often depicts a white work boot on a blue background and may be accompanied by the phrase “safety shoes required.” This means that closed-toed shoes are required in a certain area. Proper footwear helps protect personnel from injuries in areas with risk of falling objects, punctures, or crushing hazards.
25. 
    25
    Shower Station This symbol depicts a person standing under a shower, with a plus sign on the right side. It indicates the location of an emergency safety shower for immediate full-body decontamination from chemical splashes or exposure.
Advertisement

Section 4 of 5:

Radiation Hazard Symbols

Download Article

1. 
   1
   Ionizing Radiation The ionizing radiation symbol is a black trefoil (three curved propeller-like blades extending from a circle) on a yellow background. Ionizing radiation refers to X-rays, gamma rays, and nuclear material. It’s one of the most common forms of radiation and can penetrate deep into the body, damaging DNA and increasing cancer risks.

   • While harmful in high doses, ionizing radiation does not pose an immediate threat in low doses.
   • Those who have experienced prolonged ionizing radiation exposure may experience burns or radiation poisoning.
2. 2
   Non-Ionizing Radiation The non-ionizing radiation symbol is typically a yellow triangle with a black antenna-like symbol emitting waves. This type of radiation includes microwaves, radio frequencies, and strong magnetic fields. Non-ionizing radiation isn’t as harmful as ionizing radiation but can cause burns, disrupt equipment, and, in some cases, interfere with medical devices.

   • Non-ionizing radiation produces heat, so prolonged exposure could put personnel at risk of burns, eye damage, and certain skin cancers. PPE, biosafety cabinets, and other protective equipment can help reduce exposure and risk.
3. 3
   Optical Radiation Hazard The standard optical radiation hazard symbol consists of a black 11-pointed star inside a yellow triangle. This type of radiation includes lasers, intense lamps, and concentrated UV beams. The sun is also a prime example. Optical radiation can cause eye injuries, skin burns, or permanent vision damage.

   • Protective eyewear, specialty laser housing, and other safety measures can help reduce the risk of injury.
Advertisement

Section 5 of 5:

Why are lab safety symbols important?

Download Article

1. Standardized lab safety symbols provide universal understanding. By standardizing these symbols, lab personnel understand exactly what they mean, no matter what lab they’re in or what language they speak. It ensures quick recognition of dangers for everyone, no matter their job, to prevent accidents and ensure compliance.

   • It’s important that lab safety symbols are displayed in areas that can easily be seen, such as on equipment, storage cabinets, chemical containers, and entry points where hazards are present.
   • In 2003, the UN established a standardized set of lab safety symbols, each depicted by a unique pictogram. This system is referred to as the Globally Harmonized System of Classification and Labeling of Chemicals.

Expert Q&A

Search

Add New Question

Ask a Question

200 characters left

Include your email address to get a message when this question is answered.

Submit

Advertisement

Tips

Submit a Tip

All tip submissions are carefully reviewed before being published

Name

Please provide your name and last initial

Submit

Thanks for submitting a tip for review!