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Laboratory and Lab Safety Signs, Symbols and Their Meanings

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

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


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 article, 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 article 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!

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.


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.

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'.


Unnati on February 11, 2020:

Describe open flame alert in lab safety symbols?

mishka on January 21, 2020:

okay but we really need more signs

Ummuhani on December 10, 2019:

Nice but need more signs

Ajisekola habeebat on November 10, 2019:

Nice bt need more signs

khareema on October 26, 2019:

Tnx so much

on September 12, 2019:

It was good but it needed more signs

Princess on September 11, 2019:

My home work is very hard i need help plz

Princess chamber on September 11, 2019:

What is the differences between jamaican and haiti coat of arm?

Bob the builder on August 22, 2019:

Can we fix it

Vincent on August 04, 2019:

Tnx for sharing your beutiful gift of knowledge to the world

Nice job

Monique on June 10, 2019:

Wonderful. Well done!

Gyang patience niri on April 22, 2019:

This has really helped me with school work

Someone u dont know! on February 25, 2019:

Wow. Also save the kids in school. Very helpful btw.

hi on February 24, 2019:

Save the polar bears

kennedy cage on February 17, 2019:

more signs needed

penguin on February 08, 2019:

that did not help

Kj St on October 29, 2018:

It was very helpful for my homework

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These information helped me a lot my home works are all done and I saw that I am satisfied with the service

Lilly on October 11, 2018:

This helped me with my school work

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Boo boo on September 26, 2018:

Thx this has really helped me with homework

Liam❤️ on September 22, 2018:

Needs more hazards and definition but pretty handy. Thnx

a dude at school on September 11, 2018:

helpful thx

Dananjaya on July 21, 2018:

It needs more hazard signs

lol on June 26, 2018:


Menchie Gadi Heguiera on June 23, 2018:


super man on April 10, 2018:

wow it is very helpful to school

Duh Asian Gurl on February 08, 2018:

Wow! This really helped a lot for my year 7 science safety task. Was only looking for the poison sign though

Midgy on February 06, 2018:

Helped me with yr 7 homework for Lab safety task. Thanks

BELLO NAKAKA BELLO on January 03, 2018:

That is great, really appreciated, indeed i learn alot.

I want more safety simbals on December 31, 2017:

Excellent it was very helpful

anonymous on December 22, 2017:

Excellent it was very helpful. And I learnt alot. Thank you.

kaka on November 08, 2017:

i love kaka

S.S on October 25, 2017:

It was no help cause i like looking for the definition with the pic and no results tho

Jeremie James on October 22, 2017:

I find it a little helpful but needs more signs and detail

Ronica on October 04, 2017:

this helps me to get good grades and make my project look neat and nice. THANK YOU ONCE AGAIN!!

angel on September 27, 2017:

Thank you. I have learn a lot and also It make my project wonderful

WhoTheHellAreYou on September 19, 2017:

i am going to say Thank You in 4 languages:

Thank You-English




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This is great! dab on them haters!

unknown on September 18, 2017:

Really good

Juanito on September 18, 2017:

this web site helped me a lot with my assignment.

unknown on September 17, 2017:

I was actually looking for the radiation sign but this is a very good website for other sign.

NICK CROMPTON on September 15, 2017:

England is my city!!!

Georgia wing on September 14, 2017:

Thank you so much this web site was last minute exsam helper thank you once again xx ;)

trisha booo on September 13, 2017:

i learn a lot on this web side we do this kind of work in school

Niger on September 06, 2017:


Manners on September 06, 2017:

Thanks.. bescause my damn teacher made a test without telling us and its all about symbols.. follow me on facebook kent perez

HawkEye on August 17, 2017:

Thank you, for i had to study different symbols and this webpage worked as my last minute helper.

madison on August 07, 2017:

thanks but this did not help at all

choco_chipzy on July 03, 2017:

This helps so much in my homework! Thank you!

wren on June 22, 2017:

thank you

Llyne Barts 012 on June 18, 2017:

Hehe. Thanks for the information. Really helpful. Keep it up.

mudassir on May 18, 2017:

what is the difference between the symbol of irritant and harmful??

huhuhu on May 07, 2017:

bre2cute I think ur talking about biohazard

Solomon Desta on May 07, 2017:

It would have been more useful if you write it separately for each departments labs.

Beryl on March 22, 2017:

Very helpful it helped me do my assignment and educational

Asah Levi on February 24, 2017:

So helpful ,it helped me with my assignment

Maryam on February 01, 2017:

helping alot

S K Sharma on January 20, 2017:


Seailtoynup on December 25, 2016:

Thank you !! This really helped me for my assignment

angelina on December 21, 2016:

really helped me with knowing symbols thanks

Charlene wooten on December 12, 2016:

What's a 0301-laboratory, chemistry what does it envoy mentioned contains and a laboratory, hematology 0305 can someone please explain to me what this means preferences from a doctor

Suresh Kumar Mandal on November 23, 2016:

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

kawaiicat777 on November 20, 2016:

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

Vibekananda champati on October 09, 2016:

Good ! but more symbols should be added.

jeremiah on September 23, 2016:

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

Lydia on September 23, 2016:

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!

wajid iqbal on September 01, 2016:

awesome bundle of thanks

samson on August 30, 2016:

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

Noah Hill on August 08, 2016:

I love this website

lol on August 06, 2016:

hi it need more pictures so pls add more

rihana on July 19, 2016:

realy thanks

nero on June 30, 2016:

Thanks it helped me a lot for my assignment

jani1 on January 05, 2016:

it was really really helpful thank you very much

xee on November 06, 2015:

it helped a lot but need more signs with xplanation

Upz on September 11, 2015:

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

Hope on August 17, 2015:

Thanks a lot it has helped a awesome!

Susan W (author) from The British Isles, Europe on August 08, 2015:

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!

Melanie Palen from Midwest, USA on August 07, 2015:

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!

ADRIAN PAUL on July 30, 2015:

Thanks for the nice blog,really appreciated it


irene on July 21, 2015:

thank you...really a big help

ghallix14 on June 28, 2015:

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

Xtiana on June 27, 2015:'was so helpful

Susan W (author) from The British Isles, Europe on June 12, 2015:

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! :-)

Jao on June 09, 2015:

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

sophia ellis on June 02, 2015:

owesome this really good , it really helped me THANKS

andz harry on January 29, 2015:

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

sydney on November 24, 2014:

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

john on November 08, 2014:

this blog makes my assignment very good

arbab on November 03, 2014:

Its really helpful for me thnku sooo much

Obuekwe Emeka on August 20, 2014:

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

datta on February 01, 2014:

i got laboratory sign meaning

shereen on January 27, 2014:

this really answer my question

bre2cute on November 03, 2013:

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

lovely_mark on September 08, 2013:

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

Susan W (author) from The British Isles, Europe on July 03, 2013:

Hi Zara,

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

Zara Thompson from New York on July 02, 2013:

Really appreciative ,thank you so much for your blog.

Firoz from India on July 01, 2013:

Really helped me. Voted up.