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December 28 , 2000


Unraveling the Mystery of the Material Safety Data Sheet (MSDS)

By Maureen Alvarez, CIH, CSP

I remember the first time I read a Material Safety Data Sheet, better known as the MSDS.  I was working as a college intern for a Fortune 500 company.  I was lucky enough to have landed an intern job within my field of study (Toxicology) and I found myself working within the Safety Department reporting to the Corporate Industrial Hygienist.  My first assignment was to alphabetize the MSDS's.  I was told there were over 1000 MSDS's to be alphabetized and I thought "how hard can that be?"

I was eager to tackle this assignment so I immediately began sorting through the pile of MSDS's to find the sheets starting with an "a".  Within minutes, I realized this was not such an easy task.  Do I sort by "product name", "chemical name", "manufacturer", "CAS number"?  Why were the MSDS's all in different formats?  Wasn't there a standard MSDS for all manufacturers to follow?

Needless to say, this first assignment with MSDS's took me several months to complete.  Since that time, some 18 years later, I still find myself reading and interpreting MSDS's.  I have read thousands and thousands of MSDS's and consider them to be essential documents for the workplace.  These documents contain important information on the chemicals being used and handled at your work location,  As a health and safety professional, you must be able to read and understand the valuable information on the MSDS.  

This article will review the major sections of an MSDS and highlight the important health and safety information that you need to be familiar with.  Let’s get started!

The MSDS typically contains the following sections:


Section I

Manufacturer's name, address, phone number, etc.


Section II

Hazardous Ingredients/Identity Information


Section III

Physical/Chemical Characteristics


Section IV

Fire and Explosion Hazard Data


Section V

Reactivity Data


Section VI

Health Hazard Data


Section VII

Precautions for Safe Handling and Use


Section VIII

Control Measures


Section IX

Special Precautions

Let's take a look at each section and review the information contained there.  If you have an MSDS available, I suggest you follow along using one of your own MSDS'.

Section I

The first section of the MSDS gives the manufacturer's name and address, trademark, product name, generic chemical names, and other names used for the chemical.  The first section also contains the emergency phone number.  The name that is on the MSDS must be the same as on the product label.  This section may also contain the date that the MSDS was prepared or the date when the information was last updated.

Section II  Hazardous Ingredients/Chemical Information

The Hazardous Ingredients section should list the names of all hazardous chemicals that make up the product, and airborne exposure limits for each chemical including OSHA Permissible Exposure Limits (PEL), ACGIH Threshold Limit Values (TLV) and any other known exposure limits for each ingredient in the product.   You should also find the Chemical Abstract Services number or CAS # for each chemical listed.  The CAS # is a registry number for every chemical, similar to our own social security numbers. 

Within this section you should also find the percent listed for each chemical ingredient with the expectation that 100% of the chemical ingredients have been listed for you.  If you find that your MSDS does not contain a list of up to 100% of the hazardous ingredients, then you should contact the manufacturer and speak to the chemist.   This person is the most knowledgeable about what is contained within the product and he/she should be able to give you the missing information.  Don't expect the chemist to give you their product formula, most often they will only be able to tell you if the missing ingredients are alcohol based, solvent based, acids, etc. and what percent of the mixture they are.

Section III Physical/Chemical Characteristics

The Physical Properties section of the MSDS provides technical, chemical information that will help the Industrial Hygienist or Safety Professional evaluate the true hazards of the material. 

Some of the more commonly listed terms are vapor pressure (how volatile the material is), vapor density (how dense the vapors are compared to air), specific gravity (will the material float or sink in water), evaporation rate, appearance and odor.

I suggest you familiarize yourself with the terms listed in this section so you will understand the properties of the materials that you have.  A good chemical dictionary will provide you with the proper definitions.

Seciton IV Fire and Explosion Hazard Data

The Fire Protection or Flammability Data section tells whether the chemical is Flammable, Combustible, Explosive or none of these.  It will also tell you the type of fire extinguisher to use for fires involving this material.

The single most important piece of information in this section is the Flashpoint.  The flashpoint is the temperature at which the material will give off enough vapors so that the vapors will ignite, or catch fire, when a spark is present.  The spark can come from a cigarette, welding, cutting or grinding, friction, static electricity or even from turning on a light switch.

If the flashpoint is <100 degrees Fahrenheit, the material is Flammable and can usually ignite from a spark at room temperature.  If the flashpoint is >100 degrees Fahrenheit, the material is Combustible and will not ignite at room temperature, it must be heated before it will give off enough vapors to ignite from a spark.

Section V  Reactivity Data

Some chemicals may need special storage conditions and may become dangerous if they are stored improperly or if they are stored wit other chemicals that they may react with.  Some chemicals should not be stored with others since they may mix and react to cause fires or explosions in the event of leaks or spills in the area where they are stored.

In this section of the MSDS there may also be information about hazardous or toxic chemicals that are generated by the breakdown of this product from a fire or extreme heat as from a welding operation.  A good example of this is the breakdown of chlorinated hydrocarbons, like 1,1,1- trichloroethane or methyl chloroform, to form a very toxic gas called phosgene, which in extreme cases can have fatal results.

Section VI Health Hazard Data

In the section on Health Effects, you will find information on the symptoms or effects from exposure to the chemical material and from overexposure to the material.  First aid information should also be present that tells you what to do in the event of harmful exposures or emergencies that occur from accidents or the improper use of this material.

This section should also tell you about the way this chemical material can effect you.  Symptoms or effects that happen while you are working with the product or shortly after are called Acute Effects.  These signs or symptom of exposure will usually go away when you leave the areas, or may get worse if you continue to work with the material.  Short term or acute effects of exposure are normally things like: dizziness, headaches, drowsiness, shortness of breath, dry irritated skin.

Chronic effects are symptoms that happen over a long period of time from exposures that are too high.  You may not normally notice these effects because they take so long to happen.  To avoid exposures that are too high, it is important to use controls like ventilation and personal protective equipment (PPE).

Section VII  Precautions for Safe Handling and Use

In this section, you will find Spill and Disposal information, Storage and Handling precautions and any other special precautions for safe use that may apply.

Generally, any spill will be handled by a Spill Response Team if is it is too big or complicated for the workers in the area of the spill to handle.  Most liquid spills should be absorbed onto spill blankets or sorbent pads and placed in an approved waste containers for disposal as hazardous waste.

Section VIII  Control Measures

In this section you will find information suggested by the chemical material manufacturer for controls to be used for this product.  The controls may include ventilation, PPE such as gloves, respirators and eye protection.  Important information may also include directions on not using this material in a confined space or only using the material in an open area.  The manufacturer may also suggest Personal Hygiene measures like washing before smoking, eating or drinking or may suggest using work uniforms or coveralls to prevent your own clothes from becoming contaminated.

Section IX  Special Precautions

In this section, you will find information about peculiar or unique problems with this material.  Generally, the information provided here is valuable regarding health and safety issues as well as product quality.  For example, the information here may suggest storage in a dark, cool area and prevent product freezing.  All of these issues pertain to maintaining the quality of the product.

As you can see, the MSDS is a long and complex document that contains important chemical, safety and health information on chemicals in the workplace.  Please become familiar with the MSDS's in your workplace.  Read and understand the precautions and information contained on the MSDS.  Most importantly, share this information with your employees by educating and training them on the chemicals in their workplace.

For more information on links to MSDS sites, please check out the links within Osh.Net at http://www.osh.net/directory/ind_hyg/hygiene_01.htm.

Copyright © 2000 by WorkCare™ All Rights Reserved

See you next month, editor@osh.net

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