Section 4: Explanation of MSDS Info
Per the OSHA Hazard Communication Standard, Visual Arts is required to ensure that material safety data sheets are readily available for all chemicals used in the department. Individuals who bring in materials from outside must keep MSDSs on hand.
Following is an explanation which is provided to help you interpret the information found on manufacturers’ MSDSs. While the format of these data sheets varies from manufacturer to manufacturer, certain components appear on each sheet.
This section gives the name and address of the manufacturer and an emergency phone number where questions about toxicity and chemical hazards can be directed.
Hazardous Ingredients of Mixtures
This section describes the percent composition of the substance, listing chemicals present in the mixture. If it was tested as a mixture, list chemicals which contribute to its hazardous nature. Otherwise, list ingredients making up more than 1% and all carcinogens.
The OSHA permissible exposure limit (PEL), National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit (REL), and/or the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) will also be listed, if appropriate. The OSHA PEL is the enforceable standard, while the others are recommended limits. The PEL is usually expressed in parts per million parts of air (ppm) or milligrams of dust or vapor per cubic meter of air (mg/m3). It is usually a time weighted average (TWA) - concentration averaged over an eight hour day. Sometimes, a STEL or short term exposure limit may be listed. The STEL is a 15 minute TWA which should not be exceeded. A ceiling limit (c), is a concentration which may not be exceeded at any time. A skin notation means that skin exposure is significant in contributing to the overall exposure.
This section outlines the physical properties of the material. The information may be used to determine conditions for exposure. The following information is usually included:
- Boiling Point: temperature at which liquid changes to vapor state
- Melting Point: temperature at which a solid begins to change to liquid
- Vapor Pressure: a measure of how volatile a substance is and how quickly it evaporates. For comparison, the VP of water (at 20ºC) is 17.5 mm Hg, Vaseline (non-volatile) is close to 0 mm Hg, and diethyl ether (very volatile) is 440 mm Hg.
- Vapor Density (air=1): weight of a gas or vapor compared to weight of an equal volume of air. Density greater than 1 indicates it is heavier than air, less than 1 indicates it is lighter than air. Vapors heavier than air can flow just above ground, where they may pose a fire or explosion hazard.
- Solubility in Water: percentage of material that will dissolve in water, usually at ambient temperature. Since the much of the human body is made of water, water soluble substances more readily absorb and distribute.
- Appearance/Odor: color, physical state at room temperature, size of particles, consistency, odor, as compared to common substances. Odor threshold refers to the concentration required in the air before vapors are detected or recognized.
Fire and Explosion Hazard Data
This section includes information regarding the flammability of the material and information for fighting fires involving the material.
- Flashpoint: the lowest temperature at which a liquid gives off enough vapor to ignite when a source of ignition is present.
- Autoignition Temperature: the approximate temperature at which a flammable gas-air mixture will ignite without spark or flame. Vapors and gases will spontaneously ignite at lower temperatures in oxygen than in air.
- Flammable Limits: the lower explosive limit (LEL) and upper explosive limit (UEL) define the range of concentration of a gas or vapor in air at which combustion can occur. For instance, an automobile carburetor controls this mixture - too lean (not enough chemical) or too rich (not enough air, as when you flood your engine), will not ignite.
- Extinguishing Media: appropriate extinguishing agent(s) for the material.
- Fire-fighting Procedures: Appropriate equipment and methods are indicated for limiting hazards encountered in fire situations.
- Fire or Explosion Hazards: Hazards and/or conditions which may cause fire or explosions are defined.
Health Hazard Data
This section defines the medical signs and symptoms that may be encountered with normal exposure or overexposure to this material or its components. Information on the toxicity of the substance may also be presented. Results of animal studies are most often given. i.e. LD50 (mouse)=250 mg/kg. Usually expressed in weight of chemical per kg of body weight. LD50 or lethal dose 50 is the dose of a substance which will cause the death of half the experimental animals. LC50 is the concentration of the substance in air which will cause the death of half the experimental animals.
Health hazard information may also distinguish the effects of acute (short term) and chronic (long-term) exposure.
Emergency and First Aid Procedures
Based on the toxicity of the product, degree of exposure and route of contact (eye, skin, inhalation, ingestion, injection), emergency and first aid procedures are recommended in this section. Additional cautionary statements, i.e., Note to Physician, for first aid procedures, when necessary, will also appear here.
This section includes information regarding the stability of the material and any special storage or use considerations.
- Stability: “unstable” indicates that a chemical may decompose spontaneously under normal temperatures, pressures, and mechanical shocks. Rapid decomposition produces heat and may cause fire or explosion. Conditions to avoid are listed in this section.
- Incompatibility: certain chemicals, when mixed may create hazardous conditions. Incompatible chemicals should not be stored together.
Spill, Leak and Disposal Procedures
This section outlines general procedures, precautions and methods for cleanup of spills. Appropriate waste disposal methods are provided for safety and environmental protection.
Personal Protection Information
This section includes general information about appropriate personal protective equipment for handling this material. Many times, this section of the MSDS is written for large scale use of the material. Appropriate personal protection may be determined by considering the amount of the material being used and the actual manipulations to be performed.
- Eye Protection: recommendations are dependent upon the irritancy, corrosivity, and special handling procedures.
- Skin Protection: describes the particular types of protective garments and appropriate glove materials to provide personal protection.
- Respiratory Protection: appropriate respirators for conditions exceeding the recommended occupational exposure limits.
- Ventilation: air flow schemes (general, local) are listed to limit hazardous substances in the atmosphere.