A Safety Data Sheet (SDS) communicates the hazards, safe handling practices, and emergency procedures for a chemical product. It is a standardized 16-section document required by OSHA’s Hazard Communication Standard, and every manufacturer or importer of a hazardous chemical must provide one. Whether you’re a worker handling chemicals, a safety manager building training programs, or a student learning workplace safety basics, the SDS is the single most comprehensive source of safety information for any chemical you encounter on the job.
The Core Purpose of an SDS
An SDS exists to answer four practical questions: What is this chemical? What can it do to me? How do I protect myself? And what do I do if something goes wrong? Every section of the document feeds into one of those questions. The format follows the Globally Harmonized System (GHS), an international framework that ensures an SDS for a chemical made in Germany looks structurally identical to one made in Texas. OSHA updated its Hazard Communication Standard in May 2024 to align with the seventh revision of the GHS, which introduced updated hazard classes, new categories like desensitized explosives, and revised requirements for several SDS sections.
How Hazards Are Communicated
Section 2 of an SDS, called Hazard Identification, is where you find the most immediately useful safety information. It includes a signal word (“Danger” for more severe hazards, “Warning” for less severe ones), hazard statements describing what the chemical can do (for example, “causes serious eye damage”), and precautionary statements telling you how to prevent exposure or respond to it.
This section also includes GHS pictograms, which are standardized symbols inside red diamond-shaped borders. There are nine pictograms, each representing a different category of risk:
- Flame: Flammable materials, self-heating chemicals, and substances that emit flammable gas
- Flame over circle: Oxidizers that can intensify a fire
- Exploding bomb: Explosives and self-reactive chemicals
- Skull and crossbones: Acutely toxic substances that can be fatal or toxic in small amounts
- Corrosion: Chemicals that cause skin burns, eye damage, or corrode metals
- Gas cylinder: Gases stored under pressure
- Health hazard (silhouette with a starburst on the chest): Carcinogens, reproductive toxins, respiratory sensitizers, and chemicals that damage specific organs
- Exclamation mark: Irritants, skin sensitizers, and chemicals with narcotic effects
- Environment: Chemicals toxic to aquatic life (this pictogram is not mandatory under OSHA but appears on many sheets)
These pictograms let you assess the broad nature of a hazard at a glance, even before reading the detailed text.
Chemical Identity and Composition
Section 1 identifies the chemical by name, lists the manufacturer’s contact information and emergency phone number, and describes the product’s recommended uses. Section 3 breaks down the composition, listing individual ingredients and their concentrations. For mixtures, any ingredient that poses a health hazard above certain concentration thresholds must be disclosed. Under the 2024 rule update, manufacturers can use prescribed concentration ranges instead of exact percentages when an ingredient’s concentration is withheld as a trade secret, but the hazard information itself still has to be fully disclosed.
What To Do in an Emergency
Sections 4 through 6 cover emergency response. Section 4, First Aid Measures, lays out what to do for each route of exposure. For eye contact, the standard guidance is to flush with large amounts of water while lifting the eyelids. For skin exposure, you remove contaminated clothing and wash the area with soap and water. For inhalation, the priority is moving the person to fresh air and keeping them warm and at rest. For ingestion, the instruction is almost always to seek medical attention immediately rather than trying to induce vomiting.
Section 5 covers firefighting, including which types of extinguishing agents work (and which ones to avoid), along with any unusual hazards the chemical creates when it burns, like toxic fumes. Section 6 addresses accidental spills or releases, describing containment methods and cleanup procedures.
Safe Handling, Storage, and Exposure Limits
Section 7 tells you how to handle and store the chemical safely, including temperature limits, ventilation requirements, and incompatible materials to keep it away from. Section 8 is one of the most practically important sections for anyone working directly with a chemical. It communicates three things: the maximum amount of the chemical you can safely be exposed to over a work shift (OSHA’s Permissible Exposure Limits), what engineering controls to use (like local exhaust ventilation or enclosed systems), and exactly what personal protective equipment you need. This goes beyond just saying “wear gloves.” It specifies the type of glove material, such as nitrile rubber versus PVC, and may include breakthrough time, which tells you how long the glove material resists the chemical before it starts to seep through.
Physical and Chemical Properties
Section 9 lists the measurable characteristics of the chemical: its appearance, odor, boiling point, flash point, pH, vapor pressure, and solubility, among others. These are based on actual tests or observations of the substance. This section matters because it tells you things like whether a liquid will evaporate quickly at room temperature (creating inhalation risk) or whether it’s heavier than air (meaning vapors could collect in low-lying areas). If a property isn’t relevant to the chemical, the SDS must note that rather than simply leaving it blank.
Stability and Toxicology
Section 10 describes the chemical’s stability: whether it can decompose dangerously under heat, what materials or conditions to avoid mixing it with, and what hazardous byproducts it can produce during breakdown. Section 11 provides toxicological information, describing the health effects of exposure by route (skin, eyes, inhalation, ingestion) and whether the chemical is linked to long-term effects like cancer, reproductive harm, or organ damage. The 2024 HCS update revised this section to better organize and present that toxicity data.
Environmental, Disposal, and Transport Information
Sections 12 through 14 cover ecological impact, disposal considerations, and shipping classifications. Section 12 describes how the chemical behaves in the environment, whether it persists in soil or water, and its toxicity to aquatic organisms. Section 13 addresses waste disposal methods. Section 14 provides transport information, including the hazard class used for shipping by road, air, or sea. These three sections fall outside OSHA’s direct enforcement authority but are required by the GHS format and are regulated by other agencies like the EPA and the Department of Transportation.
Regulatory and Revision Details
Section 15 lists other safety, health, and environmental regulations that apply to the chemical beyond OSHA’s Hazard Communication Standard. This can include reporting requirements under environmental laws or state-specific right-to-know regulations. Section 16 provides the date the SDS was prepared or last revised, along with any other useful information the manufacturer wants to include, such as a key to abbreviations used throughout the document.
Together, these 16 sections give you a complete picture of a chemical’s risks and the practical steps to work with it safely. The information flows from the most urgent (identification and hazards) to the most specialized (regulatory status), so even if you only read the first few sections, you walk away with the most critical safety details.