A Visual Guide to Science Safety Symbols in a Laboratory

Being aware of and understanding the signs in your laboratory is vital for good lab maintenance and day-to-day safety. The environment that you work in every day is bursting with flammable objects, hazardous chemicals, delicate instruments and items that need to be handled with special care. To protect employees, it’s imperative that adequate signage is in place to warn and enlighten staff and visitors to potential risks.

You’ll see numerous signs and symbols throughout the lab and it’s the job of everyone who enters to know precisely what they mean.

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General Warning

At a glance: This is one of the most common signs you’re likely to see in a lab. The symbol denotes a General Warning and acts as a broad reminder that the area you’re working in is likely to contain hazards and risks and you should work accordingly. You’re likely to find this sign on equipment, cupboards and even doorways.

Stay safe: Every time you see this sign, consider it a reminder to act with care.

General Warning Scientific Symbol


At a glance: The equipment or receptacles that you’re dealing with have likely been in contact with biohazardous materials and therefore run the risk of being contaminated. If a lab is working with infectious agents, this sign should mark the area accordingly.

Stay Safe: The rules for staying safe when working with biohazardous materials are three-fold:

  1. Be sure to wear appropriate protection. Gloves and goggles could be sufficient or certain situations could call for full suits to protect the entire body from potentially infectious diseases.
  2. Areas signposted with this symbol should be decontaminated regularly and cleaned thoroughly.
  3. An effective policy must be in place to limit potential leaks. Whatever position you hold in the lab, it is your duty to be aware of the risks associated with biohazards and know how to limit them.

Bio hazard Science Safety Symbol

Explosive Material Hazard

At a glance: This symbol indicates that chemicals with explosive properties are present in the area. This could include unstable explosives that cause dangerous chemical reactions. It could also refer to self-reactive substances and chemical mixtures that can cause explosions in the absence of air.

Stay Safe: Be sure to have a fire and explosion policy that everyone who uses the lab is aware of. Store all chemicals safely and securely and keep the area free from unnecessary hazards.

Explosive Material Hazard Safety Symbol

Flammable Material

At a glance: This sign commonly occurs in labs and suggests that flammable materials are likely to be present.

Stay Safe: Ensure that any ignitable substances are clearly labelled with the appropriate signage. These types of materials include solvents and even harsh cleaning materials. Be sure to keep such chemicals away from heat, open flames and any other heat sources that could cause them to ignite.

Flammable Material Safety Symbol

Toxic Material

At a glance: You’ll find this sign in areas where substances are held that could prove harmful to humans if they are inhaled, ingested or they come into contact with skin.

Stay Safe: The effects of such substances coming into contact with human tissue can vary depending on the material and its concentration so be sure to have protocols and risk assessments in place for every scenario. Masks, goggles and gloves should all be used when in the presence of toxic material.

Safety Symbol For Toxic Materials

Non-Ionising Radiation

At a glance: You’ll find this symbol in areas where non-ionising radiation is present. This includes the full spectrum of ultraviolet, visible light, infrared, microwave, radio frequency and extremely low frequencies.

Stay Safe: All sources of non-ionising radiation should be clearly marked. Exposure to non-ionising radiation can be limited through personal protective equipment, engineering controls and biological safety cabinets.

Non-Ionising Radiation Safety Symbol

Ionising Radiation

At a glance: This symbol denotes that ionising radiation (in other words, radiation that has enough energy to liberate electrons from atoms or molecules and ionise them) is present. You’ll likely see the symbol where x-ray equipment, medical beam canons and particle accelerators are found.

Stay Safe: Protective clothing must be worn, and the area should be avoided by all but the necessary staff members.

Ionising Radiation Safety Symbol

Low Temperature

At a glance: The symbol denotes low temperature or cryogenic hazards. These substances are often below freezing point and stored with chemicals such as liquid nitrogen.

Stay Safe: When dealing with equipment such as this, it is vital that personal protective equipment is worn. This includes but is not limited to thick rubber gloves that reach to the elbows, closed-toe footwear, rubber aprons and face shields.

Low Temperature Safety Symbol

UV Light Hazard

At a glance: This sign indicates areas where ultraviolet light is present.

Stay Safe: Exposure to ultraviolet light can range from ulcerations on the skin to skin cancer. Be sure to wear appropriate PPE and avoid the area where possible.

UV Light Hazard Safety Symbol

Oxidising Material

At a glance: This symbol indicates the presence of oxidising materials such as bromine, chlorates, nitrates, perchloric acid and peroxides

Stay Safe: The oxygen made by these materials can increase the chance of fire or explosion and some will have toxic and corrosive properties that can be harmful to the skin. Take added fire safety precautions and wear Personal Protective Equipment such as gloves, goggles and face shields.

Oxidising Material Safety Symbol

Laser Beam Hazard

At a glance: The sign denotes the presence of laser beams.

Stay Safe: Direct exposure to laser beams has the potential to damage eyes and skin. Lab staff must wear appropriate protective clothing that is non-flammable to protect against potential fire hazards.

Laser Beam Hazard Safety Symbol


Optical Radiation Hazard

At a glance: This symbol suggests that optical radiation is present, this includes ultraviolet radiation, visible light and infrared.

Stay Safe: Protective clothing and equipment is necessary when dealing with optical radiation. In particular, radiation-producing lasers must have the beam path for the laser system enclosed, and users should double check to ensure there are no unwanted reflections before using the laser.

Optical Radiation Hazard Safety Symbol

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