An SDS, or Safety Data Sheet, 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 manufacturer or importer of a hazardous chemical is required to produce one, and every employer who uses that chemical must keep the SDS accessible to workers. If you’ve encountered the term at work, in a lab, or on a product label, the SDS is essentially the chemical’s complete safety profile in a consistent, internationally recognized format.
What an SDS Contains
Every SDS follows the same 16-section structure, established by the Globally Harmonized System (GHS), an international framework for chemical safety communication. This standardization means that whether you’re reading an SDS for a cleaning solvent in Texas or an industrial adhesive in Germany, the information appears in the same order and covers the same categories.
The 16 sections, in order, are: identification, hazard identification, composition and ingredients, first-aid measures, firefighting measures, accidental release (spill) measures, handling and storage, exposure controls and personal protective equipment, physical and chemical properties, stability and reactivity, toxicological information, ecological information, disposal considerations, transport information, regulatory information, and other information. Sections 12 through 15 are included for completeness but fall under other agencies’ authority, not OSHA’s.
For most workers, the sections that matter day to day are the first few. Section 1 tells you what the product is and who manufactures it. Section 2 lays out the specific hazards, including pictograms and signal words like “Danger” or “Warning.” Section 3 lists the chemical ingredients and their concentrations. Section 4 covers first-aid steps for different types of exposure: skin contact, eye contact, inhalation, and ingestion. Section 8 tells you what protective equipment to wear.
GHS Pictograms and What They Mean
One of the most recognizable features on an SDS (and on chemical labels) is the set of diamond-shaped pictograms with red borders. There are nine standard symbols, each representing a different category of hazard:
- Flame: Flammable materials, self-heating chemicals, or substances that emit flammable gas
- Flame over circle: Oxidizers, which can intensify a fire
- Exploding bomb: Explosives and self-reactive chemicals
- Skull and crossbones: Acutely toxic substances that can be fatal or toxic with short-term exposure
- Corrosion: Chemicals that cause skin burns, serious eye damage, or corrode metals
- Gas cylinder: Gases stored under pressure
- Health hazard (person with starburst on chest): Long-term health risks like cancer, reproductive harm, organ damage, or respiratory sensitization
- Exclamation mark: Less severe hazards like skin or eye irritation, allergic skin reactions, or narcotic effects
- Environment (dead tree and fish): Toxic to aquatic life (this one is non-mandatory in the U.S.)
These pictograms give you a fast visual summary before you read the detailed text. A product showing both the skull-and-crossbones and the corrosion symbol, for example, tells you immediately that you’re dealing with something that’s both acutely toxic and capable of burning skin or eyes on contact.
How SDS Differs From the Old MSDS
If you’ve been in a workplace long enough, you may remember Material Safety Data Sheets, or MSDSs. The SDS replaced the MSDS when the U.S. adopted the GHS format. The key difference is standardization. MSDSs had no required section order, so the same information could appear on page 2 of one sheet and page 8 of another. The 16-section GHS format eliminated that inconsistency, making it faster to find critical safety information in an emergency.
Workplace Access Requirements
OSHA’s Hazard Communication Standard (1910.1200) requires employers to keep SDSs for every hazardous chemical in the workplace and make them immediately accessible to employees during every work shift. “Immediately accessible” means workers should not have to leave their work area to find the information.
Employers can use physical binders, computers, tablets, or any other system, as long as there are no barriers to access. If SDSs are stored electronically, there must be a backup plan for power outages or system failures so employees can still reach the information in an emergency. For workers who travel between job sites during a shift, the SDSs can be kept at the primary workplace, but the employer must ensure those workers can get the information immediately if something goes wrong.
SDSs can also be integrated into operating procedures or organized by work area rather than individual chemical, as long as the required information for each hazardous chemical is still fully covered and accessible.
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 affect several SDS sections, including hazard identification (Section 2), composition (Section 3), physical and chemical properties (Section 9), and toxicological information (Section 11).
Notable changes include a new hazard class for desensitized explosives, updated criteria for classifying flammable gases and aerosols, and revised approaches to skin corrosion and eye damage classification that promote non-animal testing methods. The rule also clarified how manufacturers can use concentration ranges instead of exact percentages when an ingredient’s concentration is considered a trade secret.
Compliance deadlines are staggered: manufacturers and importers of single substances have 18 months from the rule’s effective date to update their labels and SDSs, while those producing mixtures have 36 months.
How to Use an SDS in Practice
You don’t need to memorize all 16 sections. In most situations, you’ll reference an SDS for one of three reasons: figuring out what protective gear to use before handling a chemical, knowing what to do if someone is exposed, or understanding how to clean up a spill safely.
For protective equipment, go to Section 8. It will specify whether you need gloves, goggles, a respirator, or other gear, and often specifies the type of glove material that resists the chemical. For first aid after exposure, Section 4 breaks down the response by route: what to do if the chemical touches skin, gets in the eyes, is inhaled, or is swallowed. For spills, Section 6 covers containment and cleanup procedures, including what absorbent materials to use and what to avoid.
Section 7 (handling and storage) is worth reading before you use a chemical for the first time. It covers temperature limits, ventilation requirements, and incompatible materials you should never store nearby. Section 10 (stability and reactivity) tells you what conditions could cause the chemical to react dangerously, such as heat, friction, or contact with water.