Lehigh Home
F&A Policies

EH&S Home
Safety Bulletin
Contact EHS
Accident Reporting
Emergency Procedures
Training and Orientation
Right to Know
Computer Disposal

Hazard Communication (Right-to-Know)

The Hazard Communication Standard
All About Chemicals
Chemical Labels
Label Systems: Colors, Numbers, and Symbols
The Material Safety Data Sheet (MSDS)
MSDS Availability
Use the MSDS to Stay Safe
Chemical Identity
Physical Hazards
Physical and chemical characteristics
Health Hazards
Avoid chemical exposures
Precautions and Controls
Practice Chemical Safety
Use of Personal Protective Equipment
Be Prepared for Emergencies
HazCom Program Availability

The Hazard Communication Standard

Chemicals play an important role in our lives, but they may also present many hazards. Chemicals are safe when handled properly, but if youíre not aware of their potential danger, you can put yourself and others at risk. You have a Right-To-Know what hazards you may encounter on the job and how to protect yourself from these hazards. That is why the Occupational Safety and Health Administration (OSHA) created the Hazard Communication Standard (HazCom).

-back to top-

All About Chemicals

You have a right-to-know

The HazCom Standard was developed to ensure that employers provide their employees with the following information:

  • Hazardous chemicals they may be exposed to and why they are considered hazardous
  • Ways to lessen chemical exposure
  • Ways to reduce the risks when working with hazardous chemicals

Remember: Chemicals are a part of modern life. We donít want to give up their benefit; but, we have to know how to handle them safely and recognize their hazards.

Two types of hazards: There are two groups of chemical hazards.

Chemicals with physical hazards may be:

  • Explosive. They can suddenly release pressure.
  • Flammable. They can catch fire easily.
  • Reactive. They can burn, explode, or release toxic vapor if exposed to other chemicals, heat, air,or water.

Chemicalsí health hazards can range from minor to deadly. They may be:

  • Corrosive. They can burn or even destroy skin or eyes on contact.
  • Toxic. They can cause illness or damage specific organs, such as the kidneys or lungs. In the worst instances, they can cause death.

-back to top-

Chemical Labels

Labels play an important role in hazard communication. OSHA requires chemical manufacturers to label every drum, cylinder, bag, or container that holds a hazardous chemical.

Every container must have a label or similar hazard warning. OSHA requires all labels include the following information:

  • The identity of the chemical
  • The name and address of the chemical manufacturer or distributor
  • Emergency phone numbers
  • Warnings about the chemicalís specific physical and health hazards
  • Signal words such as - DANGER, CAUTION, or WARNING
  • Procedures, protective clothing, and equipment needed to work safely with the chemical
  • First aid instructions
  • Special instructions concerning children.

Valuable information is found on labels. Always read the label before you move, handle, or open a chemical container.

If you remove a chemical from its original container, you must label it with one of the following label systems:

-back to top-

Label Systems: Colors, Numbers, and Symbols

The hazard warnings on chemical labels can appear in words, colors, numbers, or symbols.

These words may give warnings about the chemical:

  • Carcinogen (causes cancer)
  • Irritant (irritates the skin or eyes)
  • Corrosive (burns the skin or eyes)

Signal words may tell how dangerous the chemical is:

  • DANGER = can cause immediate serious injury or death
  • WARNING = can cause moderate injury or death
  • CAUTION = can cause relatively minor injury

Labels can use color to show the type of hazard:

  • RED = Fire Hazard
  • BLUE = Health Hazard
  • YELLOW = Reactivity Hazard
  • WHITE = Special hazard or protective equipment is required

Numbers can be used along with colors to show the degree of a hazard:

  • 4 = Extreme hazard
  • 3 = Serious hazard
  • 2 = Moderate hazard
  • 1 = Slight hazard
  • 0 = Minimal hazard

Additional information on a particular chemical, can be found on the Material Safety Data Sheet (MSDS).

-back to top-

The Material Safety Data Sheet (MSDS)

The MSDS is an important right-to-know tool. It contains detailed chemical and safety information. Each chemical in the workplace must have an MSDS that identifies:

  • The chemical
  • The chemicalís hazard or hazards
  • The conditions that make it most hazardous
  • How to protect yourself, other people, and the environment from its hazards
  • What to do in an emergency involving the chemical.

MSDSs are written and distributed by the chemical manufacturers or importers. They are sent with the initial shipment of the chemical.

-back to top-

MSDS Availability

Copies of MSDSs should be available in your work area. If they are not, check with your supervisor. If an MSDS can not be found for a chemical in your area, other resources should be used to obtain the MSDS:

  • ē A Sigma-Aldrich CD-Rom MSDS database is available at the EH&S office.
  • MSDSs are available on the World-Wide-Web (WWW). Site addresses are listed on Environmental Health and Safety's web site.
  • Lab Stores has MSDSs for chemicals it purchases.
  • Call Environmental Health and Safety at X84251 to request a copy of an MSDS.

-back to top-

Use the MSDS to Stay Safe

An MSDS contains the information needed to work safely with a chemical. Review the following pages to become familiar with key terms found on an MSDS ó and why theyíre important.

-back to top-

Chemical Identity

The MSDS tells you what the chemical is, including:

  • Common and chemical names
  • Names of any hazardous ingredients
  • Name, address, and telephone number of the chemical manufacturer, importer, or other firm that provided the MSDS so additional information can be obtained or they can be contacted in an emergency.

Also found on the MSDS is a measure of how much of the chemical you can be exposed to without damaging your health. This may be:

  • Permissible Exposure Limit (PEL), the maximum air contaminant a person can be exposed to on a repeated basis without developing adverse effects, as specified by OSHA regulations; or,
  • Threshold Limit Value (TLV), the daily air concentration in which the American Conference of Governmental Industrial Hygienists (ACGIH) believes persons may be exposed to without adverse effect.

-back to top-

Physical Hazards

The MSDS tells you if a chemical will:

  • Catch fire
  • Explode
  • React dangerouslyif exposed to air, water, or other chemicals, and what conditions and substances to keep it away from.

Information alerting you to fire and explosion hazards may include:

  • Flash point: Minimum temperature at which a flammable liquid's vapor could catch fire if it comes in contact with a spark or other ignition source. Lower numbers mean a greater fire hazard.
  • Upper and lower flammable or explosive limits (UFL, LFL, UEL, LEL): Minimum and maximum amounts of vapor in the air that could catch fire or explode if they contact an ignition source.

-back to top-

Physical and chemical characteristics

The MSDS lists many chemical properties on how a chemical will behave under different conditions.

Normal appearance and odor:
Characteristics helpful in recognizing the chemical.
Boiling point:
Temperature at which a liquid boils or changes to a vapor.
Melting point/freezing point:
Temperature at which a chemical changes from solid to liquid or liquid to solid.
Solubility in water:
How much of the chemical will dissolve in water.
Specific gravity:
A mass-to-volume comparison relative to water.
(1). A specific gravity below 1 will float in water, above 1 will sink in water.
Vapor density:
Compares a chemicalís vapor density to air density.
(1). A vapor density below 1 will rise in air, above 1 will sink in air.
Vapor pressure:
The higher the number, the faster a chemical evaporates, increasing inhalation risk.

-back to top-


Identifies conditions that might cause dangerous chemical reactions.

Whether a chemical is prone or resistant to breakdown over time; conditions to avoid (heat, shock, pressure, etc.) to prevent hazardous reactions.
Specific chemicals, air, or water that could cause a dangerous reaction with the chemical.
Hazardous decomposition products:
Whether the chemicalís breakdown or reaction will create new hazardous products like toxic gases.
Hazardous polymerization:
Whether a chemical will react by itself, releasing heat that could lead to an explosion.

-back to top-

Health Hazards

Itís very important to know what health problems could develop from exposure to a chemical. To help you understand the results of overexposure, the MSDS explains:

  • Routes of chemical exposure (inhaling, swallowing, eye, or skin contact)
  • Type of exposure (acute or chronic)
  • Specific health effects from exposure (e.g., skin irritation or burns, breathing problems, reproductive problems)
  • Organs that might be affected (e.g., lungs or liver)
  • Whether the chemical may cause cancer (carcinogenic)
  • Signs and symptoms of exposure (e.g., headaches, nausea, dizziness, rashes).

-back to top-

Avoid chemical exposures

The MSDS also lists medical conditions that could be worsened by exposure to the chemical. If you have asthma, a heart condition, or any problem thatís listed on the MSDS, immediately alert your supervisor. You may need to take extra precautions to avoid contact with that chemical.

The MSDS also tells what to do if you are overexposed. First aid instructions to follow while waiting for medical help may include:

  • Flushing eyes at an emergency eyewash station
  • Removing contaminated clothing and thoroughly washing skin
  • Getting to fresh air after inhaling a chemical.

Remember: If you work with chemicals, report any possible overexposure symptoms to your supervisor immediately!

-back to top-

Precautions and Controls

An MSDS contains more than warnings. It has instructions and information on ways to reduce the risk of chemical accidents and health problems from exposure. It may cover:

  • Personal protective equipment, such as respirators or eye protection
  • Hygiene practices, such as washing hands after working with the chemical
  • Engineering controls, such as ventilation
  • Instructions for handling and storing the substance properly and safely, such as avoiding heat sources.

  • Clean up spills and leaks
  • Put out fires
  • Dispose of the chemical properly.

-back to top-

Practice Chemical Safety

Before you start any job, use the following safety checklist.

  • Look around for anything that could go wrong.
  • Eliminate the risks before you start.
  • Check and read labels and MSDSs.
  • Use the correct protective clothing and equipment.
  • Remove from the work space anything you could trip over or that creates a hazard ó ignition sources, reactive chemicals, combustibles, etc.
  • Be sure equipment is in good working order. If itís not, DONíT USE IT. REPORT IT TO YOUR SUPERVISOR.
  • Donít eat or smoke in the work area.
  • Use proper ventilation.
  • Use the right tool or equipment for the job.
  • Follow Standard Operating Procedures.
  • Keep focused on what you are doing.

-back to top-

Use of Personal Protective Equipment

Different chemicals and jobs require different levels of protection. Select equipment based on procedures established for your work area. You may have to wear:

  • Safety glasses or goggles
  • Protective clothing or suits
  • Gloves
  • Boots or shoes
  • Respirators.

-back to top-

Be Prepared for Emergencies

  • Know the location and how to use each piece of emergency equipment
  • Know how to handle a small spill, leak, or fire
  • Know your evacuation route and where to go in case of an emergency.

-back to top-

HazCom Program Availability

Your right-to-know about chemical hazards and protection does not stop with putting information on labels and using MSDSs. Lehigh University has developed a written Hazard Communication Program. Copies of the program are available at the following locations:

  • Environmental Health and Safety, 616 Brodhead Avenue
  • Student Health Center, Johnson Hall, Room 36
    (Contact Director of Student Health)
  • University Police Department, Johnson Hall, Room 221
    (Contact Chief of Police)
  • Mountaintop Campus, Facilities Services, Iacocca Hall, Room C11
    (Contact Assistant Director)

Lehigh employees may review the Hazard Communication Program to ensure they are informed concerning workplace health and safety hazards, especially chemical hazards.

-back to top-


Environmental Health and Safety schedules Hazard Communication training seminars each semester. The training seminars are offered to personnel who work in laboratories and also non-laboratory personnel who work with chemicals. An individual should attend a training session if:

  • they work with chemicals and have not been trained,
  • the chemicals they work with have changed since their original training, or
  • they have not attended a graduate student safety orientation series held each August.

Call X84251 if you need additional information on Hazard Communication training.

-back to top-


Back to F&A Home
F&A Policies

Lehigh University • 616 Brodhead Avenue • Bethlehem, PA 18015 • 610.758.4251