List of Laboratory Safety Symbols and Their Meanings
Table of Contents
1. General Warning
2. Biohazard
3. Flammable Material Hazard
4. Explosive Material Hazard
5. Electrical Hazard
6. High Voltage Hazard
7. Toxic Material Hazard
8. Ionizing Radiation Hazard
9. Non-Ionizing Radiation Hazard
10. Low Temperature Hazard
11. Hot Surface Hazard
12. UV Light hazard
13. Oxidizing Material Hazards
14. Corrosive Material Hazard
15. Glassware Hazards
16. Carcinogen Hazard
17. Irritant
18. Health hazard
19. Gloves required
20. Boots Necessary
21. Protective Clothing
22. Safety Glasses
23. Breathing mask/Respirators
24. Face shield
25. Hearing protection
26. Eye Wash Station
27. Safety Shower
28. Wash hands
29. Food & Drink Prohibited
30. No Pacemakers or Metallic Implants
31. Fire Extinguisher
32. Fire Blanket
33. Fire Hose
34. No open flames
35. First Aid Station
36. Defibrillator
37. Emergency meeting point
38. Harmful irritant
39. Laser beam hazards
40. Optical radiation hazard
41. IAEA Ionizing Radiation Hazard
42. Dangerous to the environment
43. Strong magnetic field
44. Recycling symbol
45. Inert Gas
46. Compressed Gas
47. Recombinant DNA
48. Non-flammable gas
49. Cold room
50. No Gloves
Following symbols warn of possible dangers in the laboratory to help
the lab professionals keep safe and informed.
1. General Warning
General Warning – It is a warning indicating the presence of hazardous
materials in the lab.
2. Biohazard
Biohazard – It provides warning on lab equipment that may contain
biohazardous materials like blood samples.
3. Flammable Material Hazard
Flammable Material hazard – Chemicals labeled as flammable have the
tendency to ignite and should be store accordingly. Keep the chemicals
away from flames, sparks, and oxidizing substances.
4. Explosive Material Hazard
Explosive material hazard – It pertains to chemicals in the lab that has
explosive properties.
5. Electrical Hazard
Electrical hazard – Electrical hazards in the lab that can cause mild
tingling and death. Devices labeled as electrical hazards should always
be turned off when not in use.
6. High Voltage Hazard
High voltage – A symbol symbolizes lightning that can cause serious
injury and even death.
7. Toxic Material Hazard
Toxic – It is a generic sign for toxic/poisonous substances and can
cause severe damage when inhaled, absorbed, or swallowed.
8. Ionizing Radiation Hazard
Ionizing radiation hazard – It denotes the presence of ionizing radiation,
which carries energy to liberate electrons from molecules/atoms and
ionizing them. Examples are x-ray equipment, accelerators, and beam
cannons.
9. Non-Ionizing Radiation Hazard
Non-ionizing radiation hazard – It warns staff of non-ionizing radiation
sources such as UV spectrum, infrared, visible light, radiofrequency,
and microwave, to name a few.
10. Low Temperature Hazard
Low temperature warning symbol – It pertains to a cryogenic hazard
inside the lab such as cold storage areas where chemicals like liquid
nitrogen are stored.
11. Hot Surface Hazard
Hot surface – It warns of the possibility of burn hazards from hot
surfaces. This symbol is usually found in lab equipment that produces
heat such as lab ovens and autoclaves.
12. UV Light hazard
Ultraviolet light hazard – It warns you of potential dangers such as
redness and ulceration of the skin. Exposure to UV light for a long
period of time can lead to skin cancer.
13. Oxidizing Material Hazards
Oxidizing agents – They transfer oxygen to another chemical substrate,
which means they can give oxygen to flammable substances. They
should be store separately from flammable substances. When dealing
with oxidizing agents, you should wear proper lab clothing including
gloves and eye protection.
14. Corrosive Material Hazard
Corrosive agents – Strong chemicals that corrode into your skin and
other substances. A drop of the corrosive agent can cause serious
damage. So, wear protective gear at all times when working with
corrosive substances.
15. Glassware Hazards
Glassware hazard – It is a physical hazard that has the tendency to
become a health hazard, especially if contaminated with toxic and
infectious substances.
16. Carcinogen Hazard
Carcinogenic hazard – It pertains to human carcinogens such as
methylene chloride, formaldehyde, and benzene. This sign suggests that
you have to wear proper personal protective equipment.
17. Irritant
It refers to substances that can irritate the eyes and toxic when inhaled
or swallowed. Protective gear must be worn when dealing with
substances tagged as irritants.
18. Health hazard
It pertains to substances that can cause serious health damage such as
respiratory problems, reproductive toxicity, and carcinogenicity.
19. Gloves required
It suggests that hand protection must be observed, especially when
handling hazardous substances. The ideal gloves to use in a lab setting
is heat and chemical resistant.
20. Boots Necessary
It means that the usual shoes are not enough for doing certain lab-
related works. Lab boots protect your feet from corrosive chemicals.
21. Protective Clothing
A lab coat/protective clothing has to be worn. There are different lab
coats and each serves a specific purpose.
22. Safety Glasses
They come in different forms – eyeshields, goggles, glasses, spectacles.
They protect the eye from chemical splashes, debris, visible light, or
radiation from ultraviolet rays.
23. Breathing mask/Respirators
It must be worn to protect respiratory health. If you see this sign, it
means you are working in a place with a potentially contaminated air.
24. Face shield
A face shield must be worn when doing experiments, especially those
that handle substances that might cause an explosion.
25. Hearing protection
Noise in the lab can be fairly loud and there are instances when hearing
protection has to be worn. Once you see this symbol, it means you will
be exposed to a dangerously high decibel and you have to wear proper
hearing protection.
26. Eye Wash Station
It shows the location of the eyewash station, which is usually adjacent
to the safety shower.
27. Safety Shower
In case of splashes and spills, the lab worker can easily access the
shower and prevent further injuries to the eyes and body.
28. Wash hands
You should wash your hands after getting rid of soiled protective
clothing, before eating, and before leaving the lab.
29. Food & Drink Prohibited
The environment is not safe for eating and drinking as such could lead
to accidental ingestion of harmful substances inside the lab.
30. No Pacemakers or Metallic Implants
Warning of strong magnetic field hazard caused by lab
instruments/equipment that make use of superconducting magnets.
31. Fire Extinguisher
Lab fires are extremely dangerous, which explains why every lab is
required to have a proper fire extinguisher.
32. Fire Blanket
It indicates the area where fire blankets are located. It is used to smother
the fire to contain and control fire.
33. Fire Hose
It informs persons of the location of the hose connections in the lab.
34. No open flames
It indicates that risks associated with an open flame device such as
lighters, matches, and Bunsen burners.
35. First Aid Station
It indicates the availability of first aid kit.
36. Defibrillator
It shows the location of the lab’s automated external defibrillator so that
you can easily locate it in times of emergency such as sudden cardiac
arrest.
37. Emergency meeting point
It is a safe place where lab employees and staff will meet in case of an
emergency situation.
38. Harmful irritant
It pertains to substances that are not corrosive but may cause
discomfort and irritation when exposed to the skin. Examples are
chloroform, ammonia, and chlorine.
39. Laser beam hazards
Exposure to laser beams can cause serious injuries. If you see this
symbol, it means you have to wear proper protective gear/clothing to
protect yourself from the damaging effects of the laser.
40. Optical radiation hazard
It warns lab personnel of equipment that has the ability to produce
radiation in the lab like high-powered lasers. If you see this label, it
means you have to wear proper gear, especially eyewear.
41. IAEA Ionizing Radiation Hazard
This symbol indicates trefoil radiation hazards, which is important as
exposure to such can lead to serious injury and even death. You can
commonly see this symbol on the device housing the radiation source.
42. Dangerous to the environment
The substance in question can cause harm to the environment. You can
see this symbol in lab chemicals toxic to marine wildlife. Such
chemicals should be disposed of properly.
43. Strong magnetic field
It alerts lab personnel of the danger that equipment with a strong
magnetic field causes, especially in people with implants and
pacemakers.
44. Recycling symbol
It is used in the lab to indicate recyclable items, particularly where such
items are gathered and sorted.
45. Inert Gas
Such type of gas does not undergo a chemical reaction under a given
condition. An example is a compressed gas cylinder of Argon or Helium.
46. Compressed Gas
This symbol is routinely used in the lab. It includes liquefied gas, non-
liquefied gas, and dissolved gas. The cylinder has a high pressure,
which makes it extremely hazardous. The gas that flows in the cylinder
may cause injury, fire, or explosion.
47. Recombinant DNA
This lab symbol is commonly found in facilities that handle recombinant
DNA.
48. Non-flammable gas
It is a division of gases usually found in the lab. Examples of non-
flammable gas are carbon dioxide, air, helium, and nitrogen. However,
they can displace oxygen and may cause asphyxiation or even death.
49. Cold room
It has a closed air circulation system and is not ideal for storing dry ice,
flammables, or liquid chemicals.
50. No Gloves
This sign indicates that gloves must be removed before handling things
like lab notebooks, writing instrument, answering phones, holding
doorknobs, or before leaving the work area to avoid spreading
chemicals.
Lab safety Rules and Precautions
Table of Contents
Safety Precautions in the laboratory in the time of Covid-19
General safety rules in the laboratory
Housekeeping safety rules
Laboratory Dress Code
Personal Protection Safety Measures
Safety Rules When Handling Chemicals
Chemistry Laboratory Safety Rules
Electrical Safety Measures
Safety Rules When Using Laser
Safety rules in the laboratory are all the more crucial,
especially now that we are in the midst of the pandemic.
The following has to be observed when you are in the
laboratory:
Safety Precautions in the laboratory in the time of Covid-19
1. Limit close contact – Distance from one another must be observed at
all times. Movement should also be limited to essential trips.
2. If possible, work remotely or stagger shifts to minimize the number of
people in the lab.
3. Observe proper hand hygiene at all times. There should be a hand
washing station and a hand sanitizing area.
4. Frequently touched surfaces must be kept clean and sanitized using
products that meet the criteria set by the Environmental Protection
Agency. It includes laboratory equipment and cabinet handles. Make
sure to wear personal protective equipment while cleaning and
sanitizing the lab.
5. If someone in the lab is positive of Covid-19, the protocols established
by the Center for Disease Control should be followed. Track the areas
used by the infected person and clean and decontaminate it using
EPA-recommended disinfectant.
General safety rules in the laboratory
1. Be mindful of the safety signs and fire alarm. In case of an emergency,
make sure you strictly follow safety and escape instructions.
2. Make sure you know your building’s evacuation procedures.
3. Know your laboratory equipment’s storage area and place of
designation, especially those needed in times of emergency like:
4. First aid kits
5. Eyewash stations
6. Safety showers
7. Fire extinguishers
8. Memorize emergency phone numbers as it is seemingly beneficial
during an emergency.
9. Appropriate warning signs must be placed and emphasized when
working in a laboratory filled with hazardous materials like
radioisotopes, lasers, biohazards, and carcinogens.
10. Avoid using open flames in the laboratory unless permitted by a
qualified supervisor.
11. Familiarize the laboratory’s settings, especially the location of fire
alarms and exits.
12. When doing a fire drill, see to it that electrical equipment is turned off
and all containers are closed.
13. Make sure that the laboratory is well-ventilated, especially if you are
working on something.
14. A big NO when inside the laboratory – eating, drinking, and chewing
gums.
15. Laboratory apparatus such as glassware should be used for laboratory
activities alone. Do not use it as a food container.
16. When using glass lab equipment, you should always check for any
signs of chipping or the presence of cracks. Inform your lab supervisor
should there be any damage to the equipment.
17. Use only equipment you are trained to handle. If you don’t know how to
use it, then don’t use it to avoid any problems.
18. Report to the lab technician if any laboratory tools and equipment are
not functioning properly. Do not attempt to do a repair on your own.
19. If you are in-charge to close the lab, do your part in making sure that all
ignition sources are closed and doors are locked.
20. As much as possible, avoid working alone in the lab.
21. Make sure you complete the experiment. If it needs to be left for some
time, see to it that there is someone looking after it. Do not leave your
experiment unattended.
22. When working with solutions or any glassware, make sure that it is
within your eye level. Do not lift it above your eye level to avoid the
solution from dripping. Do not smell or taste chemicals as they can be
extremely hazardous.
23. Follow proper lab waste disposal procedures.
24. Any incidents that resulted in broken equipment, tools, and injuries
should be reported no matter how minor it is.
25. If you sustained an injury, ask for help immediately.
26. If the chemicals you are working with splashes into your eyes or skin,
immediately flush with running water for at least 20 minutes.
27. Inform your supervisor the soonest time possible if you notice any
unsafe conditions.
Housekeeping safety rules
1. Keep your work area clean at all times.
2. Make emergency stations accessible and unobstructed, specifically
emergency showers, eyewash stations, exit areas, and fire
extinguishers.
3. Work areas are designated for materials and tools used for lab-related
works.
4. When storing items on the cabinet, the heavy materials should be
placed at the bottom while the light materials should be stored on top.
5. Keep solids away from the lab sink.
6. Equipment that needs ventilation (airflow) must be kept clear to avoid
overheating.
Laboratory Dress Code
There are clothing materials that must be worn inside the laboratory and there
are those that need not be worn such as shorts and skirts. When going inside
the laboratory, make sure that the following is carefully observed:
1. Hair that is chin-length or longer must be tied back.
2. Keep loose clothing and dangling jewelry secure. As much as possible,
do not wear them in the laboratory.
3. Use proper footwear. Do not wear sandals or open-toed shoes. The
footwear should completely cover the foot.
4. Wearing the proper clothing is a must. Do not wear shorts or skirts.
5. Remove acrylic nails when working with fire or things that could ignite
fire such as lighted splints, matches, and Bunsen burners.
Personal Protection Safety Measures
It pertains to what lab personnel should wear to protect themselves from lab
hazards and to observe proper hygiene, and avoid contamination.
1. Wear face shields and safety glasses when working with hazardous
materials, chemicals, heat, and glassware.
2. Gloves should be worn when handling toxic or hazardous agents.
3. A smock or lab coat is worn when performing laboratory experiments.
4. Wash your hands before entering and after leaving the lab using clean
water and soap.
5. When working with chemicals and performing experiments in general,
you should refrain from touching your eyes, mouth, face, and other
sensitive areas of the body.
Safety Rules When Handling Chemicals
Chemicals are one of the must-have items in the laboratory. Safety rules in
handling chemicals in the laboratory have to be followed to avoid spills and
chemical-related accidents.
1. All chemicals in the lab setting must be treated as dangerous.
2. Make sure that chemicals will not come in contact with your skin.
3. Chemicals should be labeled correctly: name, concentration, date
received, and the name of the person responsible for it.
4. Read the label a few times before pouring the content from a chemical
bottle.
5. Take only the chemical you need.
6. Unused chemicals should not be put back in the original container.
7. Chemicals and other laboratory solutions and materials should not be
taken away from the lab.
8. Chemicals should not be mixed in the sink drain.
9. The fume hood is the designated place for chemicals tagged as volatile
or flammable.
10. In the case of chemical spills, it should be cleaned immediately.
11. Observe proper chemical waste disposal.
Chemistry Laboratory Safety Rules
1. Check the materials you are going to use and be aware of the hazards
they bring.
2. Exercise extreme caution when refluxing, distilling, and transferring
highly volatile liquids.
3. Pour chemicals from a large container to a smaller container.
4. Do not pour chemicals back into the stock container.
5. Never tap vacuum flask.
6. Be very mindful when handling chemicals. Do not mix, measure, or
heat chemicals in front of your face.
7. Avoid pouring water into concentrated acid. The best way is to pour the
acid slowly into the water while constantly stirring the water.
Electrical Safety Measures
Electrical equipment can be found in a laboratory setting. It prevents errors in
using electronic instruments, electric shocks, and other related injuries. The
following has to be observed when dealing with electrical equipment in the
lab:
1. Ask permission from your laboratory supervisor before using high-voltage
equipment.
2. Make sure you do not modify or change the setting of high-voltage
equipment.
3. When attaching a high-voltage power supply, make sure you turn it off.
4. Use one hand when adjusting high-voltage equipment. Your other hand
should be placed behind your back or in your pocket.
5. As much as possible, do not use extension cords.
Safety Rules When Using Laser
Many labs use lasers and lab personnel must strictly follow safety precautions
when working with a laser to prevent injuries.
1. Never look into the laser beam even if it is tagged as low power or safe
for your eyes.
2. Whenever lasers are present, you have to protect your eyes by
wearing the right goggles. There are different types of laser-related
injuries but the most common ones are caused by scattered laser light
that reflects off the shiny surface of the side of the mirror, optical
tables, and mountings. If you are wearing goggles, your eyes will be
protected from laser’s scattered light.
3. Make sure your head is not at the same level as the laser beam. The
laser beam should be below or at chest level.
4. Avoid laser beams from spreading into the lab by using beam stops.
5. Avoid walking through the laser beams.
