A Safety Data Sheet (SDS) is a document that tells you exactly how to handle, store, and respond to emergencies involving a specific chemical. Every hazardous chemical used in a workplace is required to have one, and employers must make them available to employees at all times during a work shift. The core purpose is simple: give workers, emergency responders, and employers the information they need to stay safe around chemicals they encounter on the job.
Why Safety Data Sheets Exist
In the United States, OSHA’s Hazard Communication Standard (29 CFR 1910.1200) makes Safety Data Sheets mandatory. The law requires that every hazardous chemical produced or used in a workplace be evaluated for its dangers, and that this information be communicated clearly to both employers and employees. The SDS is the primary vehicle for that communication.
Before 2012, these documents were called Material Safety Data Sheets (MSDSs), and their format varied wildly from one manufacturer to another. Finding a specific piece of information, like what protective gloves to wear or what to do after skin contact, could mean hunting through pages of inconsistently organized text. In 2012, OSHA aligned with the United Nations’ Globally Harmonized System (GHS) of Classification and Labelling of Chemicals, which replaced the old MSDS with a standardized 16-section SDS format used internationally. Now, no matter who manufactured the chemical or what country it came from, the same type of information appears in the same numbered section every time.
What an SDS Actually Contains
Every SDS follows the same 16-section structure. Sections 1 through 11 and Section 16 are mandatory under OSHA rules. Sections 12 through 15 (covering ecology, disposal, transport, and regulatory information) may be included but are not required by OSHA, though they often appear because international regulations call for them. Here’s what the key sections cover:
- Section 1, Identification: The product name, manufacturer’s contact information, emergency phone number, and recommended uses.
- Section 2, Hazard Identification: The hazard classification, signal word (like “Danger” or “Warning”), pictograms, and precautionary statements. This is your quick snapshot of how dangerous the chemical is.
- Section 3, Composition: The chemical name, CAS number (a unique identifier for every chemical), and concentration. For mixtures, it lists every ingredient that poses a health hazard above certain thresholds.
- Section 4, First-Aid Measures: What to do if someone inhales, swallows, or gets the chemical on their skin or in their eyes. It also describes the most important symptoms to watch for.
- Section 5, Fire-Fighting Measures: Which extinguishing methods work, which ones to avoid, and what hazardous fumes the chemical might produce when it burns.
- Section 6, Accidental Release Measures: Step-by-step guidance for spills or leaks, including how to contain them (covering drains, for example) and how to clean up safely.
- Section 7, Handling and Storage: Safe handling practices, chemicals it should never be mixed with, and storage conditions like temperature and ventilation requirements.
- Section 8, Exposure Controls/Personal Protection: Occupational exposure limits, what engineering controls to use (like ventilation hoods), and exactly what protective equipment you need, down to the specific type of glove material and how long it holds up against the chemical.
- Section 9, Physical and Chemical Properties: Measurable characteristics like appearance, odor, flash point, pH, melting point, and vapor pressure.
- Section 10, Stability and Reactivity: Whether the chemical is stable under normal conditions, what conditions to avoid (heat, sunlight), what materials it reacts dangerously with, and what harmful byproducts it can break down into.
- Section 11, Toxicological Information: Health effects from short-term and long-term exposure, including whether the chemical is a known or suspected carcinogen and how it enters the body.
How Workers Use an SDS Day to Day
If you work with chemicals, the SDS is your go-to reference before you open a container for the first time. Section 8 tells you whether you need safety goggles, a respirator, or chemical-resistant gloves, and which specific type. Section 7 tells you whether a chemical needs to be kept away from heat or stored separately from other materials in the stockroom. These aren’t abstract recommendations. They’re the practical details that prevent burns, poisoning, and fires.
In an emergency, the SDS becomes even more critical. If a coworker splashes a chemical in their eyes, Section 4 tells you exactly what first-aid steps to take. If a container tips and spills across the floor, Section 6 walks you through containment and cleanup. If a fire breaks out in a storage area, Section 5 tells firefighters which extinguishing agents are safe to use and which could make the situation worse.
Employer Obligations for SDS Access
OSHA requires employers to make Safety Data Sheets readily accessible during every work shift, in the area where employees are working. “Readily accessible” means you should never have to ask a supervisor or search through a locked office to find one. Many workplaces keep physical binders near chemical storage areas, while others use digital systems on computers or tablets. Either approach is fine as long as every employee can pull up the relevant SDS without delay.
Employers are also required to train workers on how to read and use an SDS as part of their hazard communication program. That training should cover how to locate Safety Data Sheets in the workplace, how to interpret the hazard information and pictograms in Section 2, and how to find the protective equipment requirements and emergency procedures relevant to their specific job tasks.
Recent Updates to the Standard
OSHA published a final rule on May 20, 2024, updating the Hazard Communication Standard to align with Revision 7 of the GHS. The changes include updated hazard classification criteria for several health and physical hazard categories, a new hazard class for desensitized explosives, and revisions to SDS Sections 2, 3, 9, and 11. The rule also finalized new provisions allowing manufacturers to use prescribed concentration ranges when withholding an ingredient’s exact concentration as a trade secret.
The transition is happening on a staggered timeline. Chemical manufacturers and importers have 18 months from the July 19, 2024 effective date to update labels and SDSs for individual substances, and 36 months for mixtures. Employers then get an additional 6 months after each of those deadlines to update their workplace labels, training programs, and hazard communication plans. During the transition period, companies can comply with either the old standard, the new one, or both.
Who Benefits Beyond the Workplace
While the SDS is fundamentally a workplace document, its usefulness extends well beyond the factory floor or lab bench. Emergency medical teams use it to identify what a patient was exposed to and what symptoms to anticipate. Firefighters reference it to understand what chemicals are stored in a burning building and how those chemicals behave under heat. Environmental cleanup crews rely on Sections 6 and 12 to figure out how a spilled chemical might affect soil or waterways and how to contain the damage.
Transportation workers handling chemical shipments use SDS information alongside shipping regulations to ensure hazardous materials are loaded, separated, and labeled correctly. Even if you never work directly with chemicals, the SDS system protects you indirectly by ensuring that everyone in the supply chain, from the manufacturer to the end user, has the same clear, standardized safety information.