A Safety Data Sheet (SDS) is a standardized document that describes the hazards of a chemical product and explains how to handle, store, and respond to emergencies involving it. Every hazardous chemical sold or used in a workplace must come with one. If you work around chemicals of any kind, from industrial solvents to cleaning supplies, the SDS is the primary document that tells you what you’re dealing with and how to protect yourself.
Why Safety Data Sheets Exist
The SDS is required under OSHA’s Hazard Communication Standard (29 CFR 1910.1200), a federal regulation designed to ensure that workers know the risks of the chemicals they encounter on the job. Chemical manufacturers, importers, and distributors are legally responsible for creating an SDS for every hazardous chemical they produce or sell, then passing it along to employers who use those chemicals.
Before the current system, the United States used a similar document called a Material Safety Data Sheet (MSDS). The problem with the old format was that it wasn’t standardized. Different manufacturers used different layouts, different terminology, and anywhere from 8 to 12 sections. A chemical made in one country might describe its hazards in a completely different way than the same chemical made somewhere else. In 2012, OSHA revised its Hazard Communication Standard to align with the United Nations’ Globally Harmonized System of Classification and Labelling of Chemicals (GHS), replacing the MSDS with the SDS. The new format is recognized in over 100 countries, so a safety data sheet for a chemical made in Germany follows the same structure as one made in Texas.
The 16-Section Format
Every SDS follows the same 16-section layout, in the same order. This makes it possible to find the information you need quickly, regardless of the manufacturer or the chemical. Here’s what each section covers:
- Section 1: Identification. The product name, manufacturer’s contact information, emergency phone number, and intended use.
- Section 2: Hazard Identification. The most critical section for quick safety decisions. It lists all known hazards, signal words (“Danger” for severe hazards, “Warning” for less severe ones), pictograms, and specific hazard and precautionary statements.
- Section 3: Composition/Ingredients. The chemical names, identification numbers, and concentrations of each ingredient. If an ingredient is a trade secret, the manufacturer can withhold the exact concentration but must provide a prescribed range.
- Section 4: First-Aid Measures. What to do if someone is exposed through inhalation, skin contact, eye contact, or ingestion. It also describes the symptoms you’d expect to see, both immediate and delayed.
- Section 5: Fire-Fighting Measures. Which extinguishing methods work (and which don’t), what hazardous byproducts the chemical creates when it burns, and what protective equipment firefighters need.
- Section 6: Accidental Release Measures. How to clean up a spill or leak safely, including containment methods and protective gear.
- Section 7: Handling and Storage. Precautions for safely working with the chemical and storing it, including which other substances it should be kept away from.
- Section 8: Exposure Controls/Personal Protection. Occupational exposure limits, recommended ventilation or engineering controls, and the specific types of personal protective equipment (PPE) needed. This section gets detailed, specifying things like the type of glove material required and how long it holds up against the chemical.
- Section 9: Physical and Chemical Properties. Measurable characteristics like appearance, odor, boiling point, and flash point.
- Section 10: Stability and Reactivity. Whether the chemical is stable under normal conditions and what could cause it to react dangerously.
- Section 11: Toxicological Information. How the chemical can enter your body, what health effects it causes (both short-term and long-term), and numerical toxicity data.
- Sections 12–15: Ecological, disposal, transport, and regulatory information. These sections cover environmental impact, safe disposal, shipping classifications, and applicable regulations. OSHA requires them to be present for international consistency but does not enforce their content, since those topics fall under other agencies like the EPA and Department of Transportation.
- Section 16: Other Information. Includes the date the SDS was prepared or last revised, along with any additional notes from the manufacturer.
GHS Pictograms and What They Mean
One of the most visible features of the modern SDS is the set of standardized pictograms: symbols printed inside a red diamond border on a white background. There are nine pictograms in total, each representing a different category of hazard. You’ll see these on both the SDS itself (in Section 2) and on the chemical’s label.
A flame means the chemical is flammable or can self-heat. A skull and crossbones indicates acute toxicity severe enough to be fatal or toxic from a single exposure. The “health hazard” symbol, which looks like a silhouette with a starburst on the chest, flags long-term dangers like cancer risk, reproductive harm, or organ damage. A corrosion pictogram warns of chemicals that can burn skin, damage eyes, or corrode metal. An exclamation mark signals less severe but still real risks like skin and eye irritation. The remaining pictograms cover oxidizers (flame over circle), gases under pressure (gas cylinder), explosives (exploding bomb), and environmental hazards (dead tree and fish).
The environmental pictogram is non-mandatory under OSHA’s standard, but you’ll still see it on many SDSs because other countries require it.
How to Use an SDS in Practice
You don’t need to read all 16 sections every time. The sections are ordered so the most urgent safety information comes first. If you need to respond to an emergency, Sections 2, 4, 5, and 6 give you hazard identification, first aid, fire response, and spill cleanup. If you’re figuring out how to work safely with a chemical day to day, Sections 7 and 8 cover handling precautions and protective equipment.
Section 8 is particularly useful for workers. It tells you the maximum concentration of a chemical you can safely breathe during a work shift (the permissible exposure limit) and specifies exactly what protection you need, whether that’s safety goggles, a specific type of respirator, or chemical-resistant gloves made from a particular material. If your employer hands you generic gloves for a task involving a specific solvent, the SDS is the document that tells you whether those gloves actually provide protection.
Your Right to Access Safety Data Sheets
If you work with or near hazardous chemicals, your employer is legally required to keep SDSs readily accessible to you during every work shift, in your work area. You should not have to ask for them. OSHA has specifically stated that requiring employees to make a request could be seen as a barrier to access. Many workplaces keep physical binders in common areas or use digital systems where SDSs can be pulled up on a computer or tablet. Either format is acceptable as long as you can get to the information without delay.
Your employer is also required to maintain a written hazard communication program and provide training so you understand how to read and use SDSs. This isn’t optional. It’s part of the same federal standard that requires the sheets themselves.
Recent Changes to the Standard
OSHA published an updated final rule on May 20, 2024, primarily aligning the Hazard Communication Standard with Revision 7 of the GHS. The update refines hazard classification criteria, adds a new hazard class for desensitized explosives, and revises several SDS sections including hazard identification, composition, physical properties, and toxicological information. It also introduces more flexibility for labeling small containers (100 ml or less).
The transition is happening on a staggered timeline. Chemical manufacturers and importers must update SDSs for individual substances by early 2026, and for mixtures by mid-2027. Employers then have additional time to update their workplace programs and training, with final compliance for mixtures required by May 2028. During the transition period, companies can comply with either the old or new version of the standard.