Material Safety Data Sheets (MSDS) are prepared by manufacturers to summarize the health and safety information about their products.

To Obtain MSDS:

  • Refer to your MSDS Reference Notebook
  • Or, call the hospital safety office (793-5060 or 444-8064).
  • Or, call the manufacturer.
  • Below is the most important information that OSHA requires to be on MSDS.
  • For assistance with interpreting and applying this information to your experiment or work situation, consult with the safety office (793-5060 or 444-8064).

Components of an MSDS


  • Trade name used on the label and inventory list.
  • Manufacturer's name, address, and emergency telephone number
  • Preparation and revision dates


  • CHEMICAL and COMMON NAMES of all the hazardous components
  • ACGIH TLV: 8-hour time-weighted average
  • OSHA PEL: 8-hour time-weighted average

    These are not necessarily proven safe levels of exposure. If the exposure limit is not listed, don't assume that a chemical is safe. Contact the EH&S Office.

  • PERCENTAGE OF THE MIXTURE (optional). The percentages do not usually add up to 100% since only the hazardous ingredients have to be listed. This is NOT a trade secret recipe.


  • VAPOR PRESSURE - a measure of a liquid's tendency to evaporate
  • VAPOR DENSITY - reflects whether a vapor or gas is lighter or heavier than air
  • APPEARANCE and ODOR - The Safety Office considers these properties as well as how you work with a hazardous material to evaluate the risks, which vary greatly depending on how a material is used.


  • FLASH POINT - the lowest temperature at which a liquid gives off enough vapors, which when mixed with air, can be easily ignited by a spark. The lower the flash point, the greater the risk of fire or explosion. Remember, it's the vapors that burn, not the liquid.


Reactivity, in this context, is the tendency for a material to chemically change or breakdown and to become more dangerous. Precautions include:

  • CONDITIONS TO AVOID - such as light or heat.
  • MATERIALS TO AVOID - for example; sodium and water will react vigorously to generate hydrogen, creating a fire hazard


If you need health hazard information that is not on an MSDS, contact the Safety Office (35060 or 48064)

  • ROUTES OF ENTRY - How a hazardous material can enter your body; Inhalation, Skin Absorption, and Ingestion
  • SHORT-TERM HEALTH EFFECTS (CHRONIC) - symptoms may be felt after repeated contact with the same hazardous material over a long period of time
  • REFERENCES that list a chemical as a carcinogen or potential carcinogen

If you are concerned about a chemical exposure you may have had, report to the Employee Health Office and bring the MSDS with you, if possible.


  • SPILL AND LEAK PROCEDURES - The Safety Office (35060 or 48064) can advise you on specific procedures and provide protective equipment. All labs should have spill kits available. According to RIH and TMH policy, the person or laboratory that creates a spill is responsible for assisting in the clean-up if he/she is not injured. For large uncontrollable spills contact 35111(TMH) of 45111 (RIH).
  • WASTE DISPOSAL - At TMH call 35060 for information on how a particular chemical should be disposed. At RIH call 48064.


The Safety Office can answer specific questions regarding ventilation and personal protective equipment for normal working conditions and emergencies. Suitable control measures are based on how a material is used.

Interpreting a Material Safety Data Sheet (MSDS)

Upon receipt of an MSDS, review the document to determine if the product contains hazardous ingredients. Some manufacturers clearly indicate hazards on the MSDS by listing the hazard potential scale from 0-4, with the higher number indicating a higher risk.

Guide to Interpreting Hazard Ratings

Hazard Potential

Reactivity Hazard Rating

Flammability Hazard Rating

Health Hazard Rating

0 = Minimal or insignificant

Normally stable, even under fire conditions; will not react with water

Materials that are normally stable; will not burn unless heated

No significant risk to health

1 = Slight

Normally stable but can become unstable at high temperatures/pressures; may react mildly with water

Materials that must be preheated before ignition will occur (liquids with flashpoints ³ 200° F)

Irritation or minor reversible injury possible

2 = Moderate

Normally unstable; reacts violently with water; will readily undergo chemical change but will not detonate

Materials that must be moderately heated before ignition will occur (liquids with flashpoints ³ 100° F and < 200° F)

Temporary or minor injury may occur

3 = Serious or high

Capable of strong detonation/explosive reaction only in the presence of a strong initiating source (i.e., heat under confinement); reacts violently with water

Materials capable of ignition under almost all normal temperature conditions (flashpoints £ 73° F and 100° F, boiling point ³ 100° F)

Major injury likely unless prompt action and medical treatment are given

4 = Sever or extreme

Readily capable of detonation or explosive decomposition at normal temperatures and pressures

Very flammable gases or very volatile flammable liquids (flashpoint £ 73° F, boiling point £ 100° F)

Life-threatening; major or permanent damage may result from single or repeated exposure

Setting up a MSDS File

Material Safety Data Sheet information should be stored in an orderly fashion and must be readily available to all employees at all times. The MSDS information is useful for establishing parameters for a safe workplace and is invaluable if emergencies involving the chemical occur.

Glossary of MSDS Terms

American National Standard Institute (ANSI) - A private, nonprofit organization that administers and coordinates U.S. efforts to establish business safety standards and guidelines

Code of Federal Regulations (CFR)- A codification of the rules published in the Federal Register by executive departments and agencies of the federal government

Chemical Abstracts service (CAS) - An index of chemical information provided by the American Chemical Society; the CAS number identifies specific chemicals indexed by the CAS

Combustible liquid - Any liquid having a flashpoint at or above 100° F (37.8° C); exception: any mixture of components with flashpoints of 200° F or higher if the total volume of that component makes up 99% of the mixture

Flammable liquids: lower explosive limit (LEL) and upper explosive limit (UEL) - The lower and upper limits of vapor and air concentration that can cause an explosion; these are reported as percentage

Flashpoint - The lowest temperature at which a liquid gives off enough vapor to be ignitable

Hazardous decomposition products - Products released upon exposure to aging, heating, burning, oxidation, or reaction; the shelf life should also be listed when applicable

National Fire Protection Association (NFPA) - Label system used to designate health, flammability, and reactivity risks associated with a product (uses a vertical line for scoring data)

Permissible exposure limit (PEL) - The minimum quantity (measured in parts per million [ppm] of chemical exposure before protective measures must be instituted; set by OSHA

Percent volatile by volume - Percentage of a liquid or solid that evaporates at room temperature; the higher the percentage, the faster the substance will evaporate

Specific gravity (SG) - Ratio of the weight of a volume of liquid to the weight of an equal volume of water at a specified temperature; if the SG is > 1.0, the liquid will sink in water, if the SG <1.0, the liquid will float in water

Threshold limit value (TLV) - An atmospheric concentration of a contaminant to which nearly all workers may be repeatedly exposed after a working lifetime, without adverse effect; a TLV < 10 indicates a very hazardous material

Threshold limit value - ceiling limit (TLV-C) - The amount of concentration that should not be exceeded, even for brief periods

Threshold limit value - short term exposure (TLV -STEL) - Maximum concentration for a continuous 15 minute exposure period; the most allowed are four such periods in a workday, with at least 60 minutes between exposure periods, as long as the allowable time-weighted average is not exceeded

Threshold limit value - time weighted average (TLV-TWA) - The allowable time-weighted average concentration for a normal 8-hour workday or 40-hour workweek

Vapor density (VD) - Relative density or weight of a vapor or gas compared with an equal volume of air; if VD is < 1.0, the vapor or gas will tend to rise in the air; if VD is >1.0, the vapor or gas will fall in the air; substances with high VD will collect in the bottom of tanks

Vapor Pressure (VP) - A measure of the pressure exerted by a saturated vapor above its liquid phase in a closed container (a high VP indicates that a liquid will evaporate easily)

Volatile - Used to describe a liquid that readily evaporates