The Hazard Communication Standard [29CFR 1910.1200] requires all manufacturers or distributors of any products containing chemicals to evaluate the chemical hazards of the product. The evaluation is performed by classifying each chemical based on published toxicological or other data to determine its physical and health hazards.
The identified hazards have to be communicated on the container label and in documents called Safety Data Sheets [SDS]. Manufacturers and distributors are required to provide safety data sheets to their clients that describe the results of the classification and all known hazards of a chemical.
Globally Harmonized System [GHS]
The Globally Harmonized System [GHS] was developed by the United Nations for international standardization of hazard classification and communication. OSHA has adopted GHS, and beginning June 2015, all manufacturers are required to prepare labels and SDS according to GHS. Some manufacturers already comply with this regulation.
GHS Label Elements
The main health and physical hazards have to be indicated on the product label by using pictograms, signal words, and standardized hazard statements. The pictograms are explained in the next paragraph. The signal word "Danger" is used for severe hazards and "Warning" is used for less severe hazards. Based on the classification of the product, the hazards are described in standardized phrases called "hazard statements". For example, a highly toxic chemical requires a statement "Fatal if inhaled or swallowed".
GHS Hazard Classes
The GHS classification further divides health and physical hazards into separate classes such as toxicity, irritation, sensitization, flammability, etc. The severity of the hazard within each class is described by the category. Some classes have five categories; other classes have only one category. Category 1 or A always represents the highest hazard within that class. The higher the category number, the lower the hazard. The classes, their categories and pictograms are as follows:
Health Hazards
Pictogram
Hazard Class
Category
Description
Corrosion
Skin corrosion
Category 1A, 1B, 1C
Irreversible skin damage
Serious eye damage
Category 1
Irreversible eye damage
Skull and Crossbones
Acute toxicity, oral
Category 1, 2, 3
Highly toxic in small amounts, serious health effects or death
Acute toxicity, dermal
Category 1, 2, 3
Acute toxicity, inhalation
Category 1, 2, 3
Health Hazard
Aspiration Hazard
Category 1, 2
May be fatal if aspirated
Sensitization, respiratory
Category 1, 1A, 1B
Induces hypersensitivity of the airways
Germ cell mutagenicity
Category 1A, 1B, 2
May cause genetic defects
Carcinogenicity
Category 1A, 1B, 2
May cause cancer
Reproductive Toxicity
Category 1A, 1B, 2
May damage fertility; may damage the unborn child
Specific target organ toxicity, single exposure
Category 1, 2
Causes damage to organs
Specific target organ toxicity, repeated exposure
Category 1, 2
Causes damage to organs through prolonged or repeated exposure
Exclamation Mark
Eye irritation
Category 2A
Causes serious eye irritation
Skin irritation
Category 2
Causes skin irritation
Acute Toxicity, oral
Category 4
Harmful if swallowed
Sensitization, skin
Category 1
May cause an allergic skin reaction
Acute toxicity, dermal
Category 4
Harmful in contact with skin
Specific target organ toxicity, single exposure, Respiratory tract irritation
Category 3
May cause respiratory irritation
Specific target organ toxicity, single exposure, Narcotic effects
Category 3
May cause drowsiness or dizziness
Hazardous to the ozone layer
Category 1
Harms public health and the environment
Environment
Hazardous to the aquatic environment, acute hazard
Category 1
Environmental hazard
Hazardous to the aquatic environment, long-term hazard
Category 1, 2
Physical Hazards
Pictogram
Hazard Class
Category
Description
Flame
Flammable liquids
Category 1, 2, 3
Flammable liquids and vapors
Flammable solids
Category 1, 2
Readily combustible solids
Aerosols
Category 1, 2
Pressurized container; may burst if heated
Desensitized explosives
Category 1, 2, 3, 4
Fire, blast, or projection hazard if the desensitizing agent is reduced
Flammable gases
Category 1, Pyrophoric gas
Flammable compressed gas
Flammable aerosols
Category 1, 2
Flammable pressurized container
Self-reactive substances and mixtures; and Organic peroxides
Type A, B, C, D, E, F, G
Thermally unstable liquid or solid that can undergo strongly exothermic reactions even without oxygen
Pyrophoric liquids; Pyrophoric solids
Category 1
Substance that can spontaneously ignite in air
Self-heating substances and mixtures
Category 1, 2
Materials other than pyrophoric materials that can react with air and without energy added. These will only ignite in large quantities or after long periods of time.
Substances and Mixtures which, in contact with water, emit flammable gases
Category 1, 2, 3
Substances that emit flammable gases when in contact with water
Explosive
Explosives
Unstable Explosive, Div 1.1, 1.2, 1.3, 1.4, 1.5
Explosive compounds and projection hazards
Self-reactive substances and mixtures; and Organic peroxides
Type A, B
Corrosion
Corrosive to Metals
Category 1
May be corrosive to metals
Flame Over Circle
Oxidizing liquids; Oxidizing solids
Category 1, 2, 3
Oxidizers. Are not combustible themselves, but may cause or intensify fires in other materials
Oxidizing gases
Category 1
Gas Cylinder
Gases under pressure
Compressed gas, Liquefied gas, Dissolved gas
Gases under pressure, may explode if heated
Refrigerated liquefied gas
May cause cryogenic burns or injury
Summary Pictograms
The image below shows the pictograms used for labeling. Underneath each pictogram is a list with classes the pictogram is used for.
Safety Data Sheets
Safety Data Sheets [SDS], formerly called Material Safety Data Sheets [MSDS], communicate the hazards associated with using chemicals. They are an important source of information for workers, lab personnel, emergency responders, and emergency medical personnel. As they often provide very limited information on safe handling procedures, they should be used in conjunction with safety guides provided by DRS and other knowledgeable sources [Prudent Practices, eEROS, textbooks, etc.] and standard operating procedures written for your group.
Managing SDS in a Laboratory
SDS can be available as electronic version or as hardcopies. A computer with internet connection is particularly useful to quickly access the latest SDS. Webpages like Sigma-Aldrich or Fisher Scientific are convenient and reliable sources for finding SDS. If no internet access is available, SDS of the most hazardous, largest volume, and most frequently used materials should either be stored on a computer accessible to everybody working in the lab, or as hardcopies in a binder.
Besides electronic access it is highly recommended to have hardcopies of highly toxic and corrosive chemicals available in the laboratory so they can be taken to the hospital if an exposure occurs.
Content of a Safety Data Sheet
In compliance with the new Hazard Communication Standard, SDS are divided into 16 sections and are required to provide the following information: