A Safety Data Sheet (SDS) contains 16 standardized sections covering everything from a chemical’s identity and health hazards to storage guidelines, exposure limits, and emergency response instructions. The format is set by OSHA’s Hazard Communication Standard, which aligns with the Globally Harmonized System (GHS) so that safety information looks the same no matter who manufactures the product. Twelve of the 16 sections are mandatory under OSHA rules, while the remaining four (environmental, disposal, transport, and regulatory information) are included in the standard format but regulated by other agencies.
Identification and Supplier Contact Info
Section 1 tells you what the chemical is and who made it. It lists the product name, recommended uses, and the name, address, and phone number of the manufacturer or importer. That address and phone number must be U.S.-based. The section also includes an emergency telephone number, typically a 24-hour line you can call after an exposure or spill.
Hazard Classification
Section 2 is where you find out how dangerous the chemical actually is. It includes the GHS hazard classification, signal words (“Danger” for more severe hazards, “Warning” for less severe ones), and hazard statements that describe the nature of the risk in plain language, such as “causes serious eye damage” or “may cause cancer.”
This section also displays pictograms: standardized symbols inside red-bordered diamonds. There are nine pictograms in total, each representing a category of hazard:
- Flame: flammable materials, self-heating chemicals, substances that emit flammable gas
- Flame over circle: oxidizers that can intensify a fire
- Exploding bomb: explosives, self-reactive chemicals, organic peroxides
- Skull and crossbones: acutely toxic substances (fatal or toxic)
- Corrosion: chemicals that cause skin burns, serious eye damage, or corrode metals
- Health hazard (person with starburst on chest): carcinogens, reproductive toxins, respiratory sensitizers, chemicals that damage specific organs
- Exclamation mark: irritants, skin sensitizers, chemicals with narcotic effects
- Gas cylinder: gases stored under pressure
- Environment (non-mandatory): chemicals toxic to aquatic life
Ingredients and Composition
Section 3 lists every hazardous ingredient in the product, along with its concentration and Chemical Abstracts Service (CAS) number, a unique identifier for each chemical substance. For mixtures, it covers all components that contribute to the product’s hazards, including impurities and stabilizing additives. If a manufacturer claims trade secret protection, the SDS must still state that a specific identity or concentration has been withheld and provide a prescribed concentration range so you have some idea of what you’re working with.
Emergency and First-Aid Information
Sections 4 through 6 focus on what to do when something goes wrong.
Section 4 (First-Aid Measures) describes the immediate care an untrained person should give after exposure. It breaks instructions down by route of exposure: inhalation, skin contact, eye contact, and ingestion. It also notes the most important symptoms to watch for, both immediate and delayed.
Section 5 (Fire-Fighting Measures) lists suitable and unsuitable extinguishing agents, any specific hazards the chemical creates during a fire (like toxic fumes), and protective equipment recommendations for firefighters.
Section 6 (Accidental Release Measures) covers spill and leak response. It includes containment and cleanup methods, personal precautions, and steps to protect the surrounding environment.
Safe Handling and Storage
Section 7 lays out how to work with the chemical safely on a daily basis. This includes precautions for handling, such as avoiding ignition sources for flammable materials, and conditions for safe storage, like temperature ranges, ventilation requirements, and incompatible materials to keep it away from. If a chemical needs to be stored in a specific type of container or kept below a certain temperature, you’ll find that here.
Exposure Limits and Protective Equipment
Section 8 is one of the most practically important sections for anyone who works with hazardous chemicals regularly. It lists occupational exposure limits, the maximum airborne concentrations of a substance that workers can be exposed to over a shift. You’ll typically see three types of limits referenced:
- OSHA Permissible Exposure Limits (PELs): legally enforceable limits, usually averaged over an 8-hour workday
- NIOSH Recommended Exposure Limits (RELs): science-based recommendations, typically averaged over a 10-hour workday
- ACGIH Threshold Limit Values (TLVs): guidelines set by an independent professional organization
Some chemicals also have short-term exposure limits (measured over 15 minutes) or ceiling values that should never be exceeded at any point. Beyond the numbers, this section describes the engineering controls (like ventilation systems or enclosed processes) and personal protective equipment (gloves, respirators, eye protection) needed to keep exposure below those limits.
Physical and Chemical Properties
Section 9 provides a detailed profile of the chemical’s physical characteristics. This is where you find measurable properties that affect how you handle, store, and respond to a substance. Required properties include:
- Appearance: physical state, color, and odor
- Flash point: the lowest temperature at which the chemical produces enough vapor to ignite
- Boiling point and melting/freezing point
- pH: how acidic or alkaline the substance is
- Vapor pressure and vapor density: how readily it evaporates and whether vapors sink or rise in air
- Flammability limits: the range of vapor concentrations in air that can ignite
- Solubility: whether it dissolves in water
- Auto-ignition temperature: the temperature at which it ignites without a spark or flame
- Particle characteristics: size and shape data relevant to dust or powder hazards
A recent update to OSHA’s Hazard Communication Standard added requirements for odor threshold and evaporation rate data in this section when that information is available.
Stability, Reactivity, and Toxicology
Section 10 tells you what conditions or materials could cause the chemical to become unstable or react dangerously. It covers incompatible materials (chemicals you should never mix or store together), conditions to avoid (heat, light, humidity), and hazardous decomposition products that could form over time or under certain conditions.
Section 11 covers toxicological information: the health effects the chemical can cause and the evidence behind those classifications. This section addresses routes of exposure (breathing it in, skin absorption, swallowing), describes symptoms of both acute and chronic exposure, and includes numerical toxicity measures when available. It also covers specific long-term effects like cancer risk, reproductive harm, and organ damage from repeated exposure. OSHA’s latest rule revision added a requirement to include information on interactive effects, meaning how the chemical’s toxicity may change when combined with other substances.
Sections 12 Through 16
The final five sections round out the SDS with information that falls outside OSHA’s direct authority but still matters for complete chemical safety management.
Section 12 (Ecological Information) describes how the chemical affects the environment, covering toxicity to fish and other aquatic organisms, how quickly it breaks down in soil or water, and whether it accumulates in living things. Section 13 (Disposal Considerations) provides guidance on how to properly dispose of the chemical and its containers, including recycling or reclamation options. Section 14 (Transport Information) includes shipping classifications for road, air, rail, and sea transport, along with any special precautions for moving the material. Section 15 (Regulatory Information) lists safety, health, and environmental regulations that apply to the product but aren’t covered elsewhere on the SDS. Section 16 (Other Information) captures the date the SDS was prepared or last revised, along with any additional information the manufacturer wants to include.
While OSHA considers Sections 12 through 15 “non-mandatory” (because they fall under other agencies’ jurisdiction), the information still appears on virtually every SDS because the GHS format calls for it and other regulatory bodies require it.
How to Access an SDS at Work
If you work with hazardous chemicals, your employer is legally required to keep SDSs for every hazardous product in your workplace and make them readily accessible during every work shift. Electronic access, such as a computer terminal or company intranet, is permitted as long as it doesn’t create any barriers to immediate access. If the power goes out or the internet drops, there needs to be a backup plan so you can still get the information you need in an emergency.