An MSDS, now formally called a Safety Data Sheet, contains 16 standardized sections that cover a chemical’s identity, its health and physical hazards, first-aid steps, fire response, spill cleanup, safe handling and storage, exposure limits and protective equipment, physical properties, reactivity, toxicology, and information on the environment, disposal, transport, and applicable regulations, closing with the date the sheet was prepared or revised. Federal regulations require this exact format so that anyone who picks up a sheet, for any chemical, anywhere in the country, finds the same information in the same order.1eCFR. 29 CFR 1910.1200 – Hazard Communication
The 16 Sections of an SDS
Every SDS follows the same 16-section layout mandated by OSHA’s Hazard Communication Standard. Sections 1 through 11 fall directly under OSHA’s authority. Sections 12 through 15 must appear on the document for consistency with the international Globally Harmonized System, but OSHA does not enforce their content because those topics fall under agencies like the EPA and the Department of Transportation.2Occupational Safety and Health Administration. 1910.1200 – Hazard Communication
Section 1 – Identification
The chemical’s name, its recommended uses, and the manufacturer’s or distributor’s contact information, including an emergency phone number.
Section 2 – Hazard Identification
A plain-language summary of the chemical’s dangers, including GHS hazard categories, the signal word (“Danger” or “Warning”), pictograms, and precautionary statements.
Section 3 – Composition and Ingredients
The chemical ingredients, their concentrations, and any trade-secret claims that might limit what the manufacturer discloses.
Section 4 – First-Aid Measures
What to do immediately after exposure through skin contact, eye contact, inhalation, or swallowing. Key symptoms to watch for also appear here.
Section 5 – Fire-Fighting Measures
Suitable extinguishing agents, agents to avoid, and any unusual fire or explosion hazards the chemical creates. Firefighters often turn here first during an incident.
Section 6 – Accidental Release Measures
Cleanup procedures for spills and leaks, containment techniques, protective equipment for the cleanup crew, and environmental precautions.
Section 7 – Handling and Storage
Safe work practices, ventilation needs, temperature limits, and chemicals that should not be stored nearby.
Section 8 – Exposure Controls and Personal Protection
Permissible exposure limits, recommended engineering controls such as fume hoods, and specific protective equipment: gloves, goggles, respirators. The right glove material for a given solvent lives here, and it is not always the one closest to hand.
Section 9 – Physical and Chemical Properties
Measurable characteristics: appearance, odor, boiling point, flash point, vapor pressure, solubility.
Section 10 – Stability and Reactivity
Whether the chemical is stable under normal conditions, what triggers dangerous reactions, and which materials it should never contact.
Section 11 – Toxicological Information
Health effects from short-term and long-term exposure, whether the chemical is a known carcinogen, lethal dose data, and target organs.
Section 12 – Ecological Information
Effects on aquatic life and the broader environment, including biodegradability and bioaccumulation potential.
Section 13 – Disposal Considerations
Proper waste disposal methods and any contaminated packaging that needs special treatment.
Section 14 – Transport Information
Shipping classifications, UN identification numbers, and packing requirements for moving the chemical by road, rail, air, or sea.
Section 15 – Regulatory Information
Other safety, health, or environmental regulations that apply to the chemical beyond the Hazard Communication Standard.
Section 16 – Other Information
The date the SDS was prepared or last revised, plus any additional information the manufacturer considers relevant.
Why the Section Numbers Matter
The fixed order is the point of the format. If you need fire response information in an emergency, you go to Section 5 on every sheet for every chemical, every time. Skin exposure? Section 4. Which respirator? Section 8. You never have to hunt.1eCFR. 29 CFR 1910.1200 – Hazard Communication
MSDS Versus SDS
The name change matters if you are comparing older documents to newer ones. The United States adopted the Globally Harmonized System of Classification and Labelling of Chemicals, an international framework the United Nations endorsed in 2003, and OSHA folded those requirements into its Hazard Communication Standard.3UNITAR. Globally Harmonized System of Classification and Labelling of Chemicals1eCFR. 29 CFR 1910.1200 – Hazard Communication The old MSDS format had no required structure. One manufacturer might place first-aid information on page two while another buried it on page six. The new SDS format locks everything into the 16-section order above. Many people still say “MSDS” out of habit, and the documents are functionally the same thing; only the format and name have changed.
The Pictograms in Section 2
Section 2 includes standardized red-bordered diamond pictograms that also appear on the chemical’s label. Each symbol represents a category of hazard, so you can identify a chemical’s most serious risks at a glance before reading the text.4Occupational Safety and Health Administration. Hazard Communication Standard Pictograms
- Flame: flammable liquids, gases, or solids, and chemicals that self-heat or emit flammable gas.
- Flame over circle: oxidizers that can intensify a fire by supplying oxygen.
- Exploding bomb: explosives and chemicals that can self-react violently.
- Skull and crossbones: acute toxicity severe enough to be fatal or toxic from brief exposure.
- Health hazard: longer-term dangers such as cancer risk, reproductive harm, respiratory sensitization, or organ damage.
- Exclamation mark: less severe hazards such as skin and eye irritation, harmful acute toxicity, or narcotic effects.
- Corrosion: chemicals that cause skin burns, serious eye damage, or corrode metals.
- Gas cylinder: gases stored under pressure that may explode if heated.
- Environment: chemicals toxic to aquatic life. This pictogram is not mandatory under OSHA but appears on many labels.
A single chemical can trigger multiple pictograms. A flammable solvent that also causes organ damage would display both the flame and the health hazard diamond. Each pictogram appears only once per label regardless of how many hazard categories it covers.4Occupational Safety and Health Administration. Hazard Communication Standard Pictograms
Where to Find the Sheet
Employers must keep a copy of the SDS for every hazardous chemical in the workplace and make it immediately available to employees during every work shift. Electronic storage is allowed, but the regulation requires that the sheet be “readily accessible,” with no barriers to access in the work area.1eCFR. 29 CFR 1910.1200 – Hazard Communication If the sheets are stored on a computer system, OSHA has said that telephone access to the hazard information during an electronic system failure is acceptable only as a temporary measure, and the actual SDS must be delivered to the site as soon as possible. An auxiliary power system is also an acceptable backup.5Occupational Safety and Health Administration. Clarification of Systems for Electronic Access to MSDSs
Outside the workplace, most chemical manufacturers publish SDS documents on their websites. A search for the product name plus “SDS” will usually bring up the current sheet. Several free online databases also aggregate sheets across manufacturers, which helps when you are dealing with an older product or a company that has changed names.