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How to Read a Safety Data Sheet (SDS)
A safety data sheet (SDS) is a standardized document, written by the manufacturer or importer of a chemical, that explains the product's hazards and how to handle, store, transport and dispose of it safely. Every SDS follows the same 16-section order, so once you know the layout you can find any answer, such as which gloves to wear (Section 8) or what to do after a splash in the eye (Section 4), in a few seconds.
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What is a safety data sheet?
An SDS is the main written source of hazard information for a chemical product. It is not a label and it is not a training course: it is a reference document that sits behind the label and gives the details that cannot fit on a bottle. Length varies from a few pages to many, depending on the product and the supplier.
The name has changed over time. Older documents were called material safety data sheets (MSDS) and had no fixed format. Since the Hazard Communication Standard was aligned with the Globally Harmonized System (GHS), the term is "safety data sheet" and the 16-section format is mandatory in the United States. See SDS vs MSDS for what changed, and What is an SDS? for a longer introduction.
The sheet is organized around the label elements you can see on the container: product identifier, signal word, pictograms, hazard statements and precautionary statements. Learn the symbols on our GHS pictogram reference, and the standard wording of each code in the hazard statement and precautionary statement references. The whole system is described on the GHS overview.
Who must provide an SDS, and who must keep one?
Under the OSHA Hazard Communication Standard (29 CFR 1910.1200), chemical manufacturers and importers must evaluate the hazards of the chemicals they produce or import and prepare a safety data sheet for each hazardous chemical. Distributors must pass the sheet along to their customers. Employers who use hazardous chemicals at work must keep a sheet for each one in the workplace and make it readily accessible to employees during their work shifts.
In other words: the supplier writes it, the supplier or distributor provides it with or before the first shipment, and the employer keeps it available. Workers have a right to see the sheet and to be trained to understand it. Read more in who must provide an SDS, the employee right to know and SDS binders and digital access.
Outside the US the duty is similar but the law differs: Canada's WHMIS, the EU's REACH and CLP, and other national GHS systems each require a sheet for classified products. See the regulations index, starting with OSHA HazCom, WHMIS and EU REACH.
Consumer products such as household cleaners follow a different path: they carry labels under consumer product laws, and a sheet is usually available on request or online. The guide on SDSs for consumer products covers this.
The 16-section format
The order of the sections is fixed by Appendix D of the HazCom standard and by Annex 4 of the UN GHS. Sections 1 to 11 and 16 are enforced by OSHA; Sections 12 to 15 are part of the format, but OSHA does not enforce their content because other agencies regulate it.
- Section 1: Identification — Product name, supplier contact details, emergency phone number and recommended uses.
- Section 2: Hazard identification — GHS classification, signal word, pictograms, hazard and precautionary statements.
- Section 3: Composition / information on ingredients — Chemical identity of substances, or the hazardous ingredients and amounts in a mixture.
- Section 4: First-aid measures — Immediate steps after inhalation, skin, eye or swallowing exposure, plus key symptoms.
- Section 5: Fire-fighting measures — Suitable and unsuitable extinguishing media, fire-specific hazards, firefighter protection.
- Section 6: Accidental release measures — Spill and leak response: personal precautions, emergency steps, containment and clean-up.
- Section 7: Handling and storage — Safe handling practices, hygiene, storage conditions and incompatible materials.
- Section 8: Exposure controls / personal protection — Occupational exposure limits, engineering controls, and PPE (gloves, eye, respiratory, body).
- Section 9: Physical and chemical properties — Appearance, odor, pH, boiling and flash point, flammability limits, vapor pressure, solubility and more.
- Section 10: Stability and reactivity — Reactivity, chemical stability, hazardous reactions, conditions to avoid and incompatible materials.
- Section 11: Toxicological information — Health effects, routes of exposure, symptoms and toxicity data such as LD50 and carcinogenicity.
- Section 12: Ecological information — Ecotoxicity, persistence, bioaccumulation, mobility in soil and other environmental effects.
- Section 13: Disposal considerations — How to dispose of the product, its residues and contaminated packaging.
- Section 14: Transport information — UN number, proper shipping name, hazard class, packing group and environmental hazards for shipping.
- Section 15: Regulatory information — Safety, health and environmental regulations specific to the product.
- Section 16: Other information — Date of preparation or last revision, change notes, abbreviations, references and disclaimers.
An overview table with who uses each section most is on the 16 sections page. Each section also has its own page with the requirements, red flags, a worked field list, common mistakes and a FAQ.
How to find a specific answer fast
You rarely need to read a sheet from top to bottom. Use this lookup table to jump to the right section for your question.
| Your question | Go to |
|---|---|
| What is this product and who makes it? | Section 1 |
| Is it dangerous? What does the label symbol mean? | Section 2 |
| What is in it? | Section 3 |
| Someone got it on their skin or in their eyes. What now? | Section 4 |
| What extinguisher or fire response should I use? | Section 5 |
| It spilled. How do I clean it up? | Section 6 |
| How do I store it, and what must be kept away from it? | Section 7 |
| What gloves, goggles or respirator? What is the exposure limit? | Section 8 |
| What is the flash point, boiling point or pH? | Section 9 |
| What does it react with? Is it stable? | Section 10 |
| What are the health effects, LD50, cancer listing? | Section 11 |
| Is it harmful to fish or the environment? | Section 12 |
| How do I dispose of it? | Section 13 |
| What is the UN number or shipping class? | Section 14 |
| Which regulations apply (TSCA, SARA, Prop 65)? | Section 15 |
| How old is this sheet? | Section 16 |
A good habit is to read the sheet in three passes. First, Section 2 for the headline hazards. Second, Sections 4 to 8 for what to do in an emergency and in everyday use. Third, the data sections (9 to 11) when you need the numbers behind a decision. Our step-by-step reading guide walks through that method.
Understanding the numbers on a sheet
Sheets use a lot of abbreviations. The ones you meet most often are the exposure limits in Section 8 (PEL, REL, TLV, STEL, Ceiling, IDLH), the flash point in Section 9, and the LD50 and LC50 values in Section 11. Each has its own guide: reading exposure limits, flash point explained and LD50 and LC50 explained. Definitions are collected in the glossary, including PEL, flash point, LD50 and CAS number.
For transport information, the classes in Section 14 are explained on the DOT hazard class page, and the colored diamond you may see on a storage building is explained in NFPA 704. Note that NFPA 704 is a fire-service marking system and is separate from the GHS label.
What an SDS cannot tell you
A safety data sheet describes the product as supplied, under normal conditions of use. It cannot know how you use the product, how much you use, how well the room is ventilated, or what else is on the bench. It is also only as good as its author: sheets vary in quality, and different suppliers may classify the same substance differently. Check the date in Section 16, compare the sheet with the label, and combine it with your own risk assessment.
Two practical warnings. First, a sheet for a pure substance does not apply to a diluted or mixed product. Second, "no data available" is not the same as "no hazard". See SDSs for mixtures and SDS update requirements for more.
Where to go next
- Look up a chemical: browse the chemical index for summaries organized in the same 16 sections.
- Have a sheet you need explained? Upload it to the free AI SDS analyzer.
- Learn the compliance side: read HazCom training requirements, labeling requirements and how long to keep SDS records.
- Browse all practical guides on the guides index.
- Understand where the data comes from: see our data sources.
Frequently asked questions
What is an SDS in simple terms?
An SDS (safety data sheet) is a standard document from the maker or importer of a chemical that describes its hazards and gives advice on safe handling, storage, first aid, fire-fighting, spills, disposal and transport. It follows a 16-section format.
How many sections does an SDS have?
Sixteen. They are always in the same order, defined by OSHA's Hazard Communication Standard and the UN GHS: identification, hazard identification, composition, first aid, fire-fighting, accidental release, handling and storage, exposure controls, physical and chemical properties, stability and reactivity, toxicological information, ecological information, disposal, transport, regulatory information and other information.
Which section tells me what gloves to wear?
Section 8, Exposure controls / personal protection. It lists recommended glove materials, eye protection and respiratory protection, along with occupational exposure limits.
Who has to give me an SDS?
Under OSHA, the chemical manufacturer or importer must prepare an SDS and the distributor must pass it on. Your employer must keep a sheet for each hazardous chemical in your workplace and let you see it during your shift.
Is an SDS the same as a label?
No. The label is on the container and gives a short summary of the main hazards. The SDS is a longer reference document with details on first aid, exposure limits, storage, toxicology and more. Both come from the same classification.