Laboratory and Lab Safety Signs, Symbols and Their Meanings

Chemicals can be harmful, so always check their hazard symbols.
Chemicals can be harmful, so always check their hazard symbols. | Source


Did you ever come across laboratory signs or symbols but did not know what they meant? Or perhaps you would like to see pictures of all the various signs you would see in a laboratory and on chemicals.

In this hub, I will be giving you a detailed description of each laboratory sign or symbol and a photograph so you can easily identify it.

Signs around the world may come differently, the signs in this hub are used internationally. Even if the sign is not exactly like the signs here but has the same symbols imprinted on it, then you can be sure that that is the symbol. The author of this article claims no responsibility to any accidents that happen in the laboratory. Always consult a scientist working in a laboratory when dealing with chemicals.

Signs in a Laboratory

A laboratory is a place where dangerous events can occur, from high voltage stations to biohazards to corrosive substances. Many people are unaware of the dangers lurking in a laboratory! To alert you of hazards such as biohazards and high voltage stations, there are hazard signs placed in laboratories. You will very commonly find hazard signs in a laboratory, alerting you to various hazards you are expected to find. However, many people may not be able to identify what these hazard symbols mean. To help you get aware of the various meanings associated with each sign, this guide has been compiled to help you do so.

In this guide, there are two sections. One section which we will deal with first, is about signs that you can be expected to find on the walls of a laboratory workplace. The second will deal with signs you can be expected to find on various chemicals and even, household substances.

Gloves required!
Gloves required! | Source

Gloves Required

This symbol means that you have to wear gloves in protection from harmful chemicals or other materials. It is recommended to always wear gloves when dealing with caustic substances and other dangerous chemicals. Most hospitals and laboratories have plastic glove dispensers, so wear gloves before you enter a hospital laboratory and other chemical analysis laboratories.

To stay safe, you can wear gloves at all times in a laboratory if you wish, to protect you from chemicals.

Always dispose hypodermic needles in a sharps container.
Always dispose hypodermic needles in a sharps container. | Source


Biohazards are microorganisms which can potentially harm or even kill living organisms. These microorganisms can include viruses, contagious and dangerous bacteria, toxins and harmful microorganisms.

You will very commonly find a sign like this in biochemistry laboratories in hospitals as scientists and laboratory technicians working there would have to analyse samples from patients in the hospitals. These samples may contain highly contagious bacteria which may potentially threaten the health of the scientist.

If you ever see this sign, always ask a scientist working in the laboratory about such biohazards. It is recommended that you always wear a face mask and anti-bacterial gloves when dealing with such substances.

You may also see this sign on the packaging of hypodermic needles, samples and living tissues to be analysed. It is common etiquette for scientists to dispose of hypodermic needles in a sharps container.

High Voltage

This sign, 'high voltage' means voltage at such a high level that if any living organism comes in contact with the electricity, the electricity will cause harm or even death. This sign is found in industrial sites and perhaps laboratories.

Always stay clear of areas marked with this sign as coming in contact with the electricity will mean serious injury or death.

Many people ask how many volts 'high voltage' is considered to be. The answer to this question remains debated but in electric power transmission, it is said to be 35,000 volts. The IET say that high voltage is over 1000 volts. In industrial sites, workers protect themselves by wearing plastic gloves and other clothing.

Defibrillator can be found here.
Defibrillator can be found here.


This sign means that you have access to a defibrillator nearby. This can be seen in hospitals, some laboratories and industrial areas.

Hot Surface
Hot Surface

Hot Surface

This sign warns you that the equipment and apparatus beside you may be extremely hot and can severely burn you. This sign can be found in laboratories with hot plates to industrial areas with hot machines and steam pipes.

If you see this sign on a piece of apparatus, do not touch, you will get severely burned!

Very cold temperature!
Very cold temperature!

Low Temperature

This sign indicates very low temperatures, much lower than freezing point. You may find this sign in chemical storage areas, for storing liquid nitrogen and other chemicals.

Do not enter these areas without the supervision of a scientist and without appropriate protection.

This is what a common eye wash station looks like.
This is what a common eye wash station looks like. | Source

Eye Wash Station

This sign indicates the location of an eye wash station. If you accidentally place foreign chemicals or substances into your eyes, always try to locate an eye wash station immediately! Although some eye wash station signs may look different, always try to locate the station if there is no sign.

A typical eye wash station looks like the picture on the right, and contains two bottles of eye wash. Eye wash is a fluid which contains saline. Saline aids the rinsing of the eye and provides relief.

However, if you do get foreign chemicals in your eyes, always go to your hospital immediately! The chemicals that entered your eye could be corrosive and could cause permanent blindness!

Laser Beam Hazard

The term 'laser' stands for 'Light Amplification by Stimulated Emission of Radiation. It is usually a direct beam of light in one colour. The colour of the laser is determined by its wavelength, the unit being a 'nanometer'.

The light can be forced into one narrow beam which has a high radiant power per unit area. Because of this, the laser is very powerful enabling it to cut metal, seal objects and is used in surgical procedures. That is why you will find laser beams in factories, hospitals and surgical theatres.

As harmless as a laser may seem, that is not quite the case. Letting your skin to come in direct contact with a laser beam can be very dangerous and can have some disastrous consequences.

The eye is the most susceptible and can be damaged the easiest. If you wear no eye protection, looking at a laser beam can cause retinal damage, leading to damage to the eye, which can cause blindness or partial blindness. Always wear appropriate eye wear, always check with the owner of the equipment which eye wear is best.

Damage to the skin can also be caused if not protected. Wear protective non-flammable clothing. Laser beams can also cause fire so do not direct at any flammable substances!

Chemical Symbols

Recognising hazard laboratory signs in a laboratory is only one part, but recognising hazard signs on chemicals and other substances is another part. Many chemicals in a laboratory are harmful. They could irritate your skin, be dangerous to the environment, corrosive or toxic. That is why hazard symbols were invented, to alert you of the various dangers associated with each chemical. Material Data Safety Sheets can also be obtained about each chemical, but if you want to know quickly which chemicals are harmful and which are not, check the packaging. The signs on the packaging can tell you whether a chemical is irritant or toxic.


This sign indicates a drop of a corrosive substance falling onto a hand and burning into the hand. The word corrosive comes from the Latin word 'corrodere' meaning to gnaw. Letting a corrosive substance come in direct contact with your skin can cause the substance to eat into your flesh, down to the bone. Not pleasant! Also, if your eyes come in contact with a corrosive material they will be permanently damaged leaving you with blindness.

An example of a corrosive substance is caustic soda, which is mainly used in soap and draining sewage areas. If you see this sign on any chemical, aways handle with extreme care and wear gloves and face protection!

Dangerous To The Environment

This is a substance which may harm or kill natural species living in the environment including aquatic species, trees and plants. Throwing a substance with this sign into a lake or drainage system is not recommended, it could harm or even kill fish in the lakes, trees and plants or other animals. A substance which is dangerous to the environment is white spirit, which is used to clean paint from objects.



This is a substance which can be ignited easily when they come near a source of fuel and burn very vigorously. Always be careful when handling substances like these!


This symbol is denoted by a large black X on an orange background which has an 'I' on the bottom right corner. The word irritant means that it will cause your skin to turn red and may blister. Whilst irritant substances may not cause too much damage, it is still advisable to wear gloves.

There is another symbol which has a black X on an orange background and has no 'I' in the bottom right corner. This symbol means that the substance is 'harmful'.

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Comments 39 comments

jabelufiroz profile image

jabelufiroz 3 years ago from India

Really helped me. Voted up.

Zara thompson profile image

Zara thompson 3 years ago from New York

Really appreciative ,thank you so much for your blog.

susi10 profile image

susi10 3 years ago from The British Isles, Europe Author

Hi Zara,

Thanks for commenting and giving such positive comments! I am glad you liked this hub!

lovely_mark 3 years ago

its good but needs more photos and the explanations art a little too long can u shorten them a little im a teacher and the kids wont really understand those long things

bre2cute 3 years ago

you helped me a lot but there is one i am trying to find and i can't find it

shereen 2 years ago

this really answer my question

datta 2 years ago

i got laboratory sign meaning

Obuekwe Emeka 2 years ago

Thanks a lot, this is really gonna help in my MCB 315 Assignment. Life Saver. Whew

arbab 2 years ago

Its really helpful for me thnku sooo much

john 2 years ago

this blog makes my assignment very good

sydney 2 years ago

Thank you very much i am a Chemical Lab Analyst it has really made me to understand well the signs and its meaning.

andz harry 22 months ago

thx for putting this out if you didn't well i ll be dead

sophia ellis 18 months ago

owesome this really good , it really helped me THANKS

Jao 18 months ago

i need the author of this, can you help me?

susi10 profile image

susi10 18 months ago from The British Isles, Europe Author

Jao - I'm the author, so if you have any questions just ask me. Thanks for the read and for commenting. It's always appreciated! :-)

Xtiana 17 months ago'was so helpful

ghallix14 17 months ago

... thank you for this,. it will help me in the laboratory..

irene 16 months ago

thank you...really a big help

ADRIAN PAUL 16 months ago

Thanks for the nice blog,really appreciated it


melbel profile image

melbel 16 months ago from New Buffalo, Michigan

Wow! This is such a helpful hub. I worked as a TA in a lab and have friends that do the same. We have to learn this and the students do too (although they often lack interest.) It's really important stuff!

susi10 profile image

susi10 16 months ago from The British Isles, Europe Author

Melanie - Thanks so much for reading this and the awesome comments. :D I agree, it's really important to know this, whether a scientist or not. There are so many home products that have these signs, and most people don't even look at them!

Hope 16 months ago

Thanks a lot it has helped a awesome!

Upz 15 months ago

It helped a lot. But it would be better with more signs in it.

xee 13 months ago

it helped a lot but need more signs with xplanation

jani1 11 months ago

it was really really helpful thank you very much

nero 5 months ago

Thanks it helped me a lot for my assignment

rihana 4 months ago

realy thanks

lol 4 months ago

hi it need more pictures so pls add more

Noah Hill 4 months ago

I love this website

samson 3 months ago

wow it was awesome ,but it need to be more explained and also need more signs because new signs have been brought out.

alott 3 months ago

wow its is amesome!!!

wajid iqbal 3 months ago

awesome bundle of thanks

Lydia 2 months ago

I'm so glad to have found this! I am doing research for a design quiz and this helped me so much - there isn't very much comprehensible information about safety signs online WITH information. So THANK YOU!

jeremiah 2 months ago

pretty good but u should put what to do in case of an accident

Vibekananda champati 2 months ago

Good ! but more symbols should be added.

GabrielTD 8 weeks ago

its supper for me to learn n0w that i now all the signs

kawaiicat777 2 weeks ago

it helped me with my homework but it needs more sighns :)

Suresh Kumar Mandal 2 weeks ago

I am working in a Chemical Laboratory. So I really got the knowledge after read this topic.

KYLE 4 days ago


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