Reading An MSDS* (And What It Means)

Section 1 provides the name, address, and telephone number of the company that produced the material, the MSDS's date of issue (or most recent revision), and the name of the material. The name of the material on the MSDS must be spelled exactly as it is on the container you receive.

If one generic MSDS is used to cover various grades of a material, all grades must be listed as well as any know synonyms. If an option number or code is used by the manufacturer to help identify the MSDS, it should appear in this section, and on every consecutive page of the MSDS

Why this Information is Important: Thousands of materials with many similar names are found in workplaces. A mistake on the supplier's part in sending the wrong sheet needs to be caught immediately, before workers put their trust in the wrong information. In addition, having the supplier's telephone number on the sheet can be a vital time-saver in the event of an accident involving the material or for requesting additional data.

Section 2 lists the product's individual hazardous chemicals and their relative percentages. The material's corresponding CAS (Chemical Abstracts Service) NO.(s) must also be listed. All ingredients that meet the OSHA Hazard Communication standard criteria of a hazardous ingredient must be indentified here.

Manufacturers may also choose to list active ingredients, significant ingredients regulated under other Federal, state, or local regulations, or a complete ingredient disclosure, including nonhazardous components. Complex mixtures recognized as single substances may be listed as single components. If any of the hazardous components is a trade secret, this will be indicated in lieu of identifying the component. Suppliers of such products must still prvide health hazard data on the MSDS and additional information to safety professinals who have a documentable need to know.

If established, the chemical's exposure limits are shown. For example, the phrase "8-hr TWA; 100 ppm or 300 mg/m3" is a guideline establishing an exposure level that should not be exceeded when averaged over an eight hour workday. See TWA in Section III. Note: Exposure limit information may alternatively be found in Section 8.

Why this Information is Important: Exposure to certain hazardous materials may be acceptable but only for periods of time not to exceed certain limits and at concentrations of the material no greater than certain limits. These limits are found on the MSDS. If a job involves exposure for greater periods of time or at higher concentrations, the worker will know that wearing protective clothing or taking other protective measures as described on the MSDS is vital to their health

Exposure levels are set for healthy adult workers, based on the average 150 lb male, age 25-44. Lower exposure levels are necessary for people at higher risk; i.e. those who are young or elderly, pregnant, smokers, etc., or workers who have already been exposed to other materials for which exposure limits have been set. Exertion also increases the effects of exposure.

Exposure to more than one hazardous substance at a time can be especially harmful, because the combined effects of more than one material can prove more damaging than the additive effects of each material (e.g. 2 + 2 = 10). This is called synergy. For example, both smoking and exposure to asbestos can cause lung cancer; however, if a smoker is also exposed to asbestos, the danger of lung cancer is far greater than just adding together the separate risks from the two exposures.

Section 3 is divided into two parts. The first part describes the material's appearance and gives an overview of the most significant immediate concerns for emergency personnel. For example:

Chlorine is a greenish-yellow gas with a pungent, suffocating odor. It is a highly toxic and corrosive gas which is irritating to the eyes and mucous membranes. Although noncombustible, it is a strong oxidizer that supports the combustion of other organic materials. It is an extremely reactive and explosive gas. Chlorine reacts with many common substances such as acetylene, ammonia, hydrogen, ether, fuel gas, hydrocarbons, turpentine, and finely divided metals.

If a material is considered a confirmed or probable carcinogen by IARC, NTP, or OSHA, a teratogen, a mutagen, toxic to aquatic life or a danger to the environment, this may also be included in the emergency overview (Note: This information may also be found in Section 2, 15 or 16.)

The second part of Section 3 provides information on the potential adverse health effects and symptoms associated with exposure to the material, its components, or known by-products. Exposure to a harmful chemical can occur through several routes of entry into the body, including eye contact, skin contact, inhalation, and ingestion (swallowing). Section 3 of the MSDS must list all of the routes of entry pertinent to this material. Acute (short-term) and chronic (long-term) helath effects, symptoms of exposure, and medical conditions aggravated by exposure must be stated. If the material is carcinogenic, that fact must be stated.

Why this Information is Important:Sickness and even death from improper exposure to certain materials can be prevented if the potential hazards are known ahead of time. Chronic effects are particularly dangerous because a worker may not experience discomfort in the presence of the material, but may develop severe health problems later in life as a result of the exposures. Some materials harm a particular organ of the body and such "target organs" (heart, liver, lungs, kidneys, etc.) would be listed.

Inhalation.The principal route of entry into the body is through inhalation. Not all materials that are bad for you actually have strong or bad odors. Many dangerous chemicals have very little odor or have the ability to quickly fatigue the sense of smell so that you are no longer aware of the odor but are still being hurt through exposure to toxic concentrations.

Contact and IngestionSome materials can pass right through the skin to react with body tissue and be absorbed into the internal organs. Eye contact with some materials (dust, liquid splashes, or solution vapor or mist) can be irritating or even cause permanent damange, resulting in blindness.

Section 3 will only list animal data if its considered relevant to human health. For example, if a material was found nontoxic in animal studies, this may be stated here. Alternatively, if a material has no human case studies or epidemiological data on which to base its toxicity, animals studies may be quoted, i.e. based on animal testing, this material is presumed to... Detailed animal data may be found in Section 11.

Section 4 describes medical and first aid treatments for accidental exposure by route of exposure (i.e. inhalation, skin, eye, ingestion). Any known antidotes that may be administered by a lay person or specially trained personnel will be indicated.

A subsection entitled Note to Physicians may also be here. This will convey specific medical information on treatment and diagnostic precedures to trained medical personnel.

Why this Information is Important:Professional medical treatment should be obtained as soon as possible after an accident. However, actions taken in the first few minutes after an exposure can make the difference between a minor and a major injury. For example, if you splash battery acid in your eeys, the more quickly you begin washing out your eyes with water, the more likely you are to save your eyesight. You should know the first aid measures for a material before you work with it.

Section 5 of the MSDS provides basic fire-fighting guidance for trained fire fighters, emergency respondants, employees, and occupational health and safety professionals. It describes the fire and explosive perperties of the material, the proper extinguishing materials, and the precautions and procedures to safely and effectively fight the fire.

Why this Information is Important:The flammable properties combined with the physical and chemical properties in Section 9 give a good indication of how hazardous a material is in a fire situation. Knowing this information, before fighting a fire, helps with preplanning response procedures and equipment.

The flash point is the lowest temperature at which a flammable liquid gives off enough vapor to form an ignitable mixture with air. At a glance you can tell from a low flash point that a material represents a fire hazard; for example, the flash point of gasoline is -43 C (-45 F). The autoignition temperature tells you how hot a material must be before it will set itself on fire witihout a flame or spark. Explosive of flammable limits (i.e lower explosive limit (LEL) and upper explosive limit (UEL)) are the minimum and maximum concentrations of a flammable gas or vapor (percent by volume in air) between which an explosion can occur if an ignition source is present.

With most fires, the greatest danger to human life comes not from the heat of the flames, but from the often toxic smoke that can quickly fill the work area. Section 5 will list any known or anticipated hazardous products of combustion. For example, carbon disulfide, when burned, produces toxic gases and irritants, including carbon monoxide and sulfur oxides.

When there is fire, and time is scare, it's imperative to know the best way to safely and quickly extinguish the fire. Some burning materials react with water and may best be smothered by foam, carbon dioxide gas, or a dry chemical. Reactivity hazards that enhance the fire, as well as the explosion potential, should also be know. For example, strong oxidizers ignite combustible materials, such as wood, paper, or oil.

Section 6 provides spill, leak, and response procedures for emergency responders and environmental professionals. It describes evacuation procedures, containment and cleanup techniques, and other emergency advice to protect the health and safety of the responders as well as the environment.

Why this Information is Important: Knowledge presented in Section 6 enables preplanning for emergency response, staff training, and placing necessary equipment in the work area to quickly contain and clean up a spill or leak. Proper containment and cleanup techniques minimize the adverse effects that can occur from an accidental release

Proper cleanup procedures for flammable materials include the use of nonsparking tools, equipment, and noncombustible absorbent materials and complete decontamination techniques after cleanup to remove any flammable residues.

Section 7 provides safe handling and storage information for employees, occupational health and safety professionals, and employers. General handling precautions and practices are described to prevent release to the environment and overexposure during contact with the material and also to minimize continued contact after handling. For example, practice good personal hygiene after using this material, especially before eating, drinking, smoking, using the toliet, or applying cosmetics. Section 7 also explains necessary storage conditions to avoid damage to containers, contact with incompatibel materials and subsequent dangerous reactions, evaporation or decomposition of the stored material, or flammable and explosive atmospheres in the storage area. For example, protect these containers from physical damage, shield them from direct sunlight, and maintain their temperature at less than 38 C (100 F).

Why this Information is Important:Stored containers cannot assumed to be safe. Containers corrode, and lids leak. Sparks or heat can cause fires or explosions. Storing incompatible materials close together can cause dangerous reactions. Knowing how to safely handle materials and prevent unsafe storage conditions protects workers from potential hazards.

Section 8 discusses methods intended for occupational health and safety professionals and employers for reducing worker exposure to hazardous materials. Exposure controls include engineering controls such as ventilation and special process conditions (e.g. isolation, enclosure), or administrative controls (e.g. training, labeling, warning devices). Section 8 also provides guidance on personal protective equipment (PPE) including respirators, safety glasses, goggles, gloves, aprons, and boots. PPE recommendations are given for anticipated normal use and emergency response during a fire, spill, leak, or accidental release.

If established, exposure limits or guidelines, such as OSHA PELs or ACGIH TL Vs may be listed in Section 2 or Section 8.

Why this Information is Important: When a job responsibility includes working directly with a hazardous material, this section of the MSDS explains what controls should be in place. If the MSDS states that exposure should not exceed a certain level (i.e. OSHA PEL) or gloves are needed to prevent skin absorption, the employer should provide the necessary controls (e.g. ventilation) and PPE to ensure safe working conditions. However, it is the employee's responsibility to use the PPE that is provided.

To reduce exposure, engineering controls in the workplace are superior to administrative controls, which are superior to personal protective equipment. Sometimes a combination is neccesary to reduce overall exposure. A trained professional, such as an industrial hygienist or a safety engineer, should determine how to most effectively minimize hazards through exposure controls.

Section 9 lists physical data, including a material's boiling point, solubility in water, viscosity, specific gravity, melting point, evaporation rate, molecular weight, etc., and appearance and odor. They can help predict how the material with act and react so safe handling procedures can be determined and appropriate pesonal protective equipment can be selected.

Why this Information is Important: Safe handling and use is ensured when it is known ahead of time how a materials will behave at different temperatures or when it is exposed to water, etc. For example, calcium metal reacts with water to generate highly flammable hydrogen gas.

If a material has a low boiling point, high vapor pressure, and a high percent volatility, it will evaporate rapidly and is very likely to be an inhalation hazard. Special ventilation or breathing apparatus may be necessay. If the material is also flammable or toxic, even stronger precautions will be necessary. In general, the highter the temperature, the more active the material, i.e. the faster it evaporates, reacts, etc.

There are many different ways that materials may react with one another. The information presented in Section 10 should list materials and circumstances that could be hazardous when combined with the material covered by the MSDS. This section provides information on chemical incompatibilities, conditions to avoid, decomposition products, and the material's stability.

Why this Information is Important: A material can be stored and handled more safely when it is known how it may react to changes in temperature or contact with other materials. This section tells if the material will polymerize (react with itself), a phenomenon that can cause a rapid build-up of heat and pressure that can lead to an explosion. The information in this section helps in making the choice of materials for containers, shelving, and PPE. For example, if the material reacts with natural rubber, a respirator or gloves made of natural rubber should not be worn, and a rubber stopper should not be used to close the bottle.

Some materials may react with common materials, or may burn, or spontaneously decompose to yield by-products that are more toxic than the starting materials themselves. For example, otherwise harmless plastic sheeting can form a deadly gas when burned, and mixing bleach (sodium hypochlorite) with ammonia gives off highly toxic and irritating chloramine.

Section 11 provides information on toxicity testing of the material and/or its components. Generally, the information reflects animal testing, although some human data will be available if accidental human poisonings have occurred and the exposure amounts are known, or if epidemiological studies have been conducted. The information in this section is intended for medical professionals, occupational health and safety professionals, and toxicologists.

Data types include acute, subchronic, and chronic studies through various routes of exposure: inhalation, ingestion, skin, eye, intraperitoneal, etc. A typical example of data found in this section is Rat, Oral, LD50: 200 mg/kg which means that 200 milligrams of the chemical per each kilogram of body weight is the lethal dose that killed 50% of a group of test rats following oral administration. These data are used to help establish the degree of hazard to humans. Data specific to a material's carcinogenicity, teratogenicity, reproductive effects, neurotoxicity, and mutagencity may also be provided.

Why this Information is Important: Toxicological data is invaluable in evaluating the potential health risks that a material may pose to exposed workers. Human evidence of health effects in exposed populations is often not available for the majority of chemicals used or produced in the workplace. Therefore, professionals must rely on toxicological animal data in order to predict the health effects that might occur in humans.

Section 12 helps in evaluating the effect a chemical may have if it's released to the environment. It may also be useful in evaluating waste treatment practices. Ecotoxicity data may include information on acute and long-term toxicity to fish and invertebrates, or plant and microorganism toxicity. Chemical behavior in the air, soil or water is important data when evaluating environmental contamination. Such information could include persistence and degradation, soil mobility, bioaccumulation, and photolytic stability.

Why this Information is Important: Ecological information can be crucial in the event of a major spill, or when determining whether or not a chemical can be safely disposed of in a landfill. If a chemical is rapidly mobile in soil, then it is not a good candidate for landfill disposal because it could potentially leach into groundwater. If a spill occurs in water, knowing ecotoxicity data and the material's behavior in water (i.e. solubility, degradation) can help determine if the spills poses a threat to fish and the best cleanup approach to avoid further environmental contamination.

Section 16 provides a location for additional information, such as list of references, keys/legends, or preparation and revision indicators. Hazard ratings defining the acute health, flammability, and reactivity hazards of a material may also be included.

Why this Information is Important: Section 16 allows flexibility for additional information and ensures a complete MSDS. Hazard rating systems in this section provide a simple, recognizable, and easily understood reference to evaluate a material's hazards.