What a material safety data sheet (MSDS) includes, section by section

Last updated 2026-07-09

What is a material safety data sheet, and what happened to the old MSDS format?

The MSDS is dead. It has a new name and a fixed shape. For decades "material safety data sheet" was the standard name for chemical hazard documents in the United States. In 2012, OSHA rewrote its Hazard Communication Standard to match the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS). The document became the Safety Data Sheet (SDS) and got a mandatory 16-section format. The transition deadline for most employers was June 1, 2016 ^[1].

So when someone says MSDS today, they almost always mean SDS. The content is similar, but the old MSDS had no fixed structure. Some manufacturers put physical hazards on page one. Others buried them in section eight. The new SDS format locks every category into a numbered section that reads the same across every chemical, every manufacturer, every country that has adopted GHS. That standardization is the whole point.

If you still have legacy MSDS documents in a binder from before 2016, they may not meet the current 29 CFR 1910.1200 requirement. OSHA expects the SDS format, not the old variable-format MSDS, for all covered hazardous chemicals in your workplace ^[1].

Learn more about the broader rule that governs these documents in our guide to hazard communication.

Which OSHA standard requires safety data sheets, and who does it cover?

The governing rule is 29 CFR 1910.1200, known as the Hazard Communication Standard or HazCom. It applies to nearly every general industry employer. Construction is covered under 29 CFR 1926.59, which pulls in 1910.1200 by reference. Maritime has its own reference at 29 CFR 1915.99 ^[1].

The standard's text says chemical manufacturers and importers "shall obtain or develop a safety data sheet for each hazardous chemical they produce or import" ^[1]. Downstream employers, meaning the businesses that buy and use these chemicals, have to keep those SDSs and make them available to employees during every shift.

Coverage is broad. If your shop uses commercial cleaning products, paints, lubricants, solvents, welding gases, or pesticides, those are hazardous chemicals under HazCom and SDSs are required. Some consumer products used in a workplace the way a consumer would use them are exempt, but that exemption is narrower than most small business owners think. When in doubt, get the SDS.

OSHA enforces SDS violations under the hazard communication citation group. In fiscal year 2023, hazard communication was the second most frequently cited OSHA standard, with 2,978 violations recorded ^[2]. Current, accessible SDSs are one of the cheapest compliance wins you can buy.

What are all 16 sections of a safety data sheet?

Here is every section, what it holds, and why a worker or employer actually needs it.

Section	Name	Core content
1	Identification	Product name, manufacturer, intended use, emergency phone number
2	Hazard(s) identification	GHS hazard classification, signal word, hazard statements, pictograms
3	Composition/ingredients	Chemical name, CAS number, concentration ranges; trade secrets may be claimed
4	First-aid measures	Exposure-specific first aid by route (skin, eyes, inhalation, ingestion)
5	Fire-fighting measures	Suitable extinguishing agents, special hazards from combustion
6	Accidental release measures	Spill cleanup procedures, containment, disposal guidance
7	Handling and storage	Safe handling practices, incompatible materials, storage temperature limits
8	Exposure controls/PPE	OSHA PELs, ACGIH TLVs, recommended PPE, engineering controls
9	Physical and chemical properties	Appearance, odor, boiling point, flash point, vapor pressure, solubility
10	Stability and reactivity	Conditions to avoid, incompatible materials, hazardous decomposition products
11	Toxicological information	Routes of exposure, symptoms, LD50/LC50 data, carcinogenicity
12	Ecological information	Aquatic toxicity, persistence, bioaccumulation (not enforced by OSHA)
13	Disposal considerations	Waste disposal methods, regulatory requirements (not enforced by OSHA)
14	Transport information	DOT, IATA, IMDG classification and UN number
15	Regulatory information	SARA 311/312 hazard categories, state right-to-know listings
16	Other information	Revision date, changes from previous version, references

Sections 1 through 11 have to be filled in ^[3]. Sections 12 through 15 must be present, but OSHA does not enforce the accuracy of those sections, because they fall under EPA and DOT jurisdiction rather than OSHA's. Section 16 is optional, though responsible manufacturers include it.

The most useful sections for a working person are 2 (what can hurt me), 4 (what to do if something goes wrong), 7 (how to handle this safely), and 8 (what PPE I need). Train your people to go straight to those four first.

What does Section 2 of an SDS tell you, and why is it the most important section?

Section 2 is the hazard identification section, and it is the first thing a worker in an emergency should read. It holds the GHS hazard classification (flammable liquid category 2, for example), the signal word (Danger or Warning), hazard statements (standardized phrases like "causes serious eye damage"), precautionary statements, and pictogram descriptions ^[3].

The signal word alone tells you the severity tier. "Danger" is the more severe category. "Warning" is the less severe one. A product with no signal word has not been classified as hazardous under GHS.

GHS hazard statements are not marketing copy. They are codified, standardized phrases. H314 means "causes skin burns and eye damage." H350 means "may cause cancer." These codes live in OSHA's Appendix C to 1910.1200, so they are not something a manufacturer invented ^[1]. When you see H-codes in Section 2, you can look them up directly in the regulation.

Precautionary statements in Section 2 (coded as P-statements) cover prevention, response, storage, and disposal at a high level. Sections 7 and 8 go deeper on handling and PPE. Section 2 is the executive summary. Those later sections are the operating instructions.

What exposure limits appear in Section 8, and how do OSHA PELs compare to ACGIH TLVs?

Section 8 lists occupational exposure limits from more than one source, usually OSHA Permissible Exposure Limits (PELs) and ACGIH Threshold Limit Values (TLVs). They are not the same number, and they do not carry the same legal weight.

OSHA PELs are legally enforceable. They are codified in 29 CFR 1910.1000 Tables Z-1, Z-2, and Z-3. The problem is that most OSHA PELs were set in 1971 and have barely changed since. For many chemicals, occupational health scientists consider the PEL outdated ^[4].

ACGIH TLVs are updated every year by the American Conference of Governmental Industrial Hygienists, a private scientific group. They are not legally enforceable, but they often reflect more current toxicology. OSHA's own annotated PEL tables acknowledge that NIOSH Recommended Exposure Limits (RELs) and ACGIH TLVs may be more protective than OSHA PELs for some substances ^[4].

Section 8 also spells out engineering controls (local exhaust ventilation, for example) and the required or recommended PPE by type: respiratory protection, gloves with material specs, eye protection, and protective clothing. This is where an SDS tells you whether nitrile gloves are enough or whether you need butyl rubber. Glove material matters because chemical resistance changes a lot from one polymer to the next.

For a closer look at how PPE requirements flow from SDS information to your written program, our hazard communication article walks through the connection.

What does Section 3 say about chemical ingredients, and can a manufacturer hide the formula?

Section 3 lists the chemical identity, CAS (Chemical Abstracts Service) registry number, and concentration or concentration range of each hazardous ingredient. For mixtures, every ingredient present at 1% or above (0.1% for carcinogens) must be listed ^[1].

Manufacturers can claim trade secret protection under 29 CFR 1910.1200(i) for specific chemical identities. If a trade secret is claimed, the SDS still has to say the information is withheld and still has to provide the hazard information. A healthcare professional treating an exposed worker can request the withheld identity from the manufacturer for medical purposes, and the manufacturer has to provide it ^[1].

Trade secret claims show up more in specialty chemical formulations and less in common industrial products. If you see "proprietary blend" in Section 3 next to a hazard classification in Section 2, that is not a red flag by itself. Just make sure the hazard information in Sections 2, 4, 7, and 8 is specific enough to act on.

The CAS number in Section 3 is your reliable cross-reference. Take a CAS number to NIOSH's Pocket Guide to Chemical Hazards ^[5] or the National Library of Medicine's toxicology databases to get independent data, regardless of what the SDS says.

What first-aid information does Section 4 give you, and when should you rely on it?

Section 4 breaks first aid down by route of exposure: inhalation, skin contact, eye contact, and ingestion. For each route, it describes symptoms and the immediate steps to take before medical care arrives.

This section is not a substitute for calling Poison Control (1-800-222-1222 in the U.S.) or getting medical attention for serious exposures. It is a bridge, something a co-worker can follow in the first two minutes of an emergency. Section 4 also notes whether delayed effects are possible and whether the attending physician needs specific information.

For corrosive chemicals, eye contact instructions in Section 4 almost always say to flush with water for 15 to 20 minutes. That matches OSHA's eyewash station guidance: emergency eyewash and shower equipment should deliver flushing fluid for at least 15 minutes, per the widely referenced ANSI/ISEA Z358.1 standard ^[6]. If your SDS says 20 minutes of flushing, your eyewash station needs to be capable of that.

One thing Section 4 will not always tell you is the antidote, because antidotes exist for very few industrial chemicals. For the ones that do (hydrogen fluoride is the notable case, where calcium gluconate is used), the SDS should say so plainly.

How do safety data sheets connect to your written hazard communication program?

An SDS is one leg of a three-part HazCom program. The other two are labels and training. Under 29 CFR 1910.1200(e), every employer with hazardous chemicals must have a written hazard communication program that describes how SDSs are obtained and maintained, where they are kept, and how employees can reach them ^[1].

The written program has to list every hazardous chemical in the workplace (the chemical inventory). Each chemical on that inventory needs a matching current SDS. The two documents are linked. If a chemical is on your inventory, the SDS must be available. If you have an SDS with no matching chemical in the workplace, that is not automatically a violation, but it creates clutter and confusion.

OSHA does not require SDSs to sit in a physical binder, though a binder works fine. Electronic systems are acceptable as long as employees can reach them during every shift without barriers. If your electronic system needs a password nobody remembers, or the computer is locked in the supervisor's office, you have an access problem ^[1].

If you need to build the written program side of this, SafetyFolio's safety program generator can produce a compliant hazard communication program in about 15 minutes, formatted for your specific chemicals and operations.

For the training piece, which is a separate requirement, see our overview of osha training.

What does an SDS say about flammability and fire hazards?

Section 5 covers firefighting: suitable extinguishing media, media that must not be used (water on certain reactive metals, for instance), specific hazards from combustion (toxic gases produced when the stuff burns), and any special protective equipment for firefighters.

Section 9 gives you the physical data behind Section 5: flash point, flammability limits, auto-ignition temperature, and vapor pressure. These numbers drive storage decisions. A liquid with a flash point below 100°F is a flammable liquid under NFPA 30 and needs to be stored in approved flammable storage cabinets, away from ignition sources ^[7].

Section 10 adds reactivity information: conditions that could trigger a dangerous reaction (heat, moisture, shock), incompatible materials, and hazardous decomposition products. This is the section that tells you not to store bleach near ammonia-based cleaners, because the decomposition products include chloramine gases.

For workplaces with lockout tagout programs involving energy sources near flammable chemicals, the flash point and auto-ignition data from Sections 9 and 10 should feed straight into your LOTO energy control procedures.

How does an SDS address environmental and disposal information in Sections 12 through 15?

Sections 12 through 15 cover ecological toxicity, disposal, transport, and regulatory listings. As noted, OSHA does not enforce these sections, but they hold real operational information.

Section 13 tells you whether the chemical is a listed hazardous waste under EPA RCRA rules and points you toward proper disposal methods. Pouring a listed hazardous waste down the drain may be legal under a de minimis exemption for tiny quantities, but often it is not, and the SDS will flag that ambiguity.

Section 14 gives you the DOT proper shipping name, UN/NA number, hazard class, and packing group. If your business ships chemicals (even small quantities in a service truck), this section is what you hand your shipping coordinator. Getting DOT classifications wrong creates both safety and regulatory risk separate from the OSHA framework.

Section 15 lists whether the substance appears on SARA Title III Section 311/312 reporting lists, California Proposition 65 listings, or state right-to-know registries. For businesses that trigger Tier II reporting under SARA 312 (generally 10,000 pounds or more of a hazardous chemical stored at any one time, with lower thresholds for extremely hazardous substances), the Section 15 data feeds straight into your annual EPA filing ^[8].

How long do you have to keep safety data sheets, and what happens when a chemical is discontinued?

OSHA requires SDSs to be kept and accessible for as long as the chemical is used in the workplace. The standard itself does not state a retention period after the chemical is gone, but OSHA's broader recordkeeping rules create a practical one.

If a worker is exposed to a hazardous chemical and later develops an occupational illness, medical records and exposure records must be retained for 30 years under 29 CFR 1910.1020 ^[9]. SDS documents count as exposure records. So if you used a solvent for five years and then dropped it, keeping the SDS for 30 years from the last date of worker exposure is the defensible move.

Electronic archiving is fine. Scan old paper SDSs and drop them in a dated folder. Thirty years of cloud storage for a few hundred PDFs costs almost nothing. Not having an SDS when a former employee files a workers' compensation or occupational disease claim costs plenty.

When a manufacturer updates an SDS, 29 CFR 1910.1200(g)(5) says the updated version must reach downstream employers within three months of the manufacturer learning of new significant hazard information ^[1]. That three-month window is real. When a supplier sends you an updated SDS, swap out the old one and note the date.

How do you train employees to use an SDS properly?

HazCom training under 29 CFR 1910.1200(h) has to cover how to read and use SDSs, more than the fact that they exist ^[1]. OSHA's standard says employees must be trained on "the details of the hazard communication program developed by the employer," including the location and availability of the written program and SDS list.

Good SDS training does three things. It shows workers where SDSs are kept (physical or digital) and how to find the one for any chemical they touch. It walks through the four operationally critical sections (2, 4, 7, and 8) using an actual SDS for a chemical in their workspace, not a generic example. And it covers what to do when an SDS is missing or outdated: stop using the chemical until one is obtained, or escalate to a supervisor.

OSHA does not set a training duration or require a test, but it does require training before initial assignment and again when new hazards are introduced. A 20-minute walkthrough with hands-on practice finding information on a real SDS beats a 90-minute lecture about chemical theory every time.

For workplaces that need broader safety orientation, the osha 30 course includes hazard communication as a topic area, though it does not replace the employer-specific SDS training your program requires.

What common mistakes do employers make with safety data sheets?

The most common citation-generating mistake is outdated or missing SDSs. A supplier reformulates a product, issues a new SDS, and never tells you. You end up with a binder holding a 2009 SDS for a product whose formula changed in 2017. The hazard classification and PEL sections may be wrong. This happens constantly in small businesses.

The second most common mistake is an SDS nobody can find. A binder in the back of the storage room with no index, or an electronic system with a folder structure nobody was trained to navigate, technically satisfies the retention requirement but fails the accessibility requirement. OSHA inspectors ask workers, not managers, where the SDSs are. If the worker cannot answer, that is a citation ^[2].

A third mistake is ignoring SDS information when picking PPE. Section 8 specifies glove material, respirator type, and eye protection level. If your workers are using latex gloves with a chemical whose SDS calls for butyl rubber, you have both a HazCom problem and a potential 29 CFR 1910.132 PPE compliance problem.

For a broader look at how an incident report connects to chemical exposure events, including what SDS information belongs in post-incident documentation, see our guide on incident reporting.

One thing that is not a violation: keeping SDSs for chemicals you no longer use. It is clutter, not a citation. Spend your energy keeping the current ones accurate and easy to reach.

Where can you get a safety data sheet if you do not have one?

The manufacturer or supplier is the primary source. Under 29 CFR 1910.1200(g)(6), a chemical manufacturer must provide an SDS with the first shipment of a product and again whenever the SDS is updated ^[1]. If you order a chemical and no SDS shows up, request one before letting workers use the product.

For common chemicals, several free databases collect SDSs. OSHA maintains links to SDS repositories, and the National Library of Medicine's toxicology databases hold data for thousands of substances ^[10]. Manufacturer websites almost always host current SDSs in a product or safety section.

For a specific industrial chemical like hydrochloric acid, our hcl safety data sheet article walks through how to read a real SDS for that substance section by section.

If you genuinely cannot get an SDS from the manufacturer (the company folded, for example), document your attempts, use available toxicology data from NIOSH or NLM to reconstruct the hazard information, and think hard about substituting the chemical for one that still has current documentation. Using a chemical with no hazard information at all is not a defensible position.

Frequently asked questions

Is an MSDS the same as an SDS?

Functionally yes. OSHA renamed the material safety data sheet to Safety Data Sheet (SDS) in 2012 when it updated the Hazard Communication Standard to match the UN's GHS system. The SDS has a mandatory 16-section format; the old MSDS had no fixed structure. If someone asks for an MSDS, give them the current SDS. The content covers the same hazard categories in a standardized layout.

How many sections does a safety data sheet have?

A safety data sheet has 16 sections under OSHA's 2012 HazCom standard (29 CFR 1910.1200). Sections 1 through 11 are required with specific content. Sections 12 through 15 must be present but OSHA does not enforce their accuracy because those sections fall under EPA and DOT jurisdiction. Section 16 is optional but commonly included and shows the document revision date.

Where does an SDS have to be kept so employees can access it?

OSHA requires SDSs to be accessible to employees during every work shift, in their work area. That can mean a physical binder, a shared drive, a tablet mounted near chemical storage, or a dedicated safety software system. The test is whether a worker can reach the SDS without barriers. If access requires asking a manager or waiting for a password, that fails OSHA's accessibility requirement under 29 CFR 1910.1200(g)(8).

What is the difference between a PEL and a TLV on an SDS?

A PEL (Permissible Exposure Limit) is the legally enforceable OSHA limit set in 29 CFR 1910.1000. A TLV (Threshold Limit Value) is published annually by ACGIH, a private scientific organization, and carries no legal enforcement weight. Most OSHA PELs date to 1971 and are considered outdated by current science. ACGIH TLVs are generally more current. Section 8 of an SDS typically lists both, and some SDSs also include NIOSH RELs.

Can an employer make their own SDS for a chemical they mix in-house?

Yes. Under 29 CFR 1910.1200(g), chemical manufacturers and employers who produce hazardous chemicals must develop or obtain an SDS for each hazardous chemical. If you mix a cleaning solution or blend a product on-site that qualifies as a hazardous chemical, you are the manufacturer and must create an SDS. That document has to meet all 16-section requirements. The OSHA HazCom standard's Appendices A through E guide the hazard classification process.

How often does a safety data sheet need to be updated?

Manufacturers must revise an SDS within three months of becoming aware of significant new hazard information, per 29 CFR 1910.1200(g)(5). There is no fixed calendar update requirement. Employers should check for updated SDSs when a supplier reformulates a product or when new toxicology data is published for a chemical they use. The revision date in Section 16 tells you when the current version was last updated.

What happens if an SDS section says information is not available?

For some chemicals, especially novel or proprietary ones, certain data points in Sections 9 through 11 may be listed as not available or not determined. That is not automatically a violation if the manufacturer genuinely lacks the data. But if critical health data like carcinogenicity or acute toxicity is missing for a chemical with known hazards, that is a quality problem with the SDS. Cross-reference NIOSH's Pocket Guide or NLM's toxicology databases for independent data.

Do safety data sheets apply to consumer products used at work?

The HazCom standard has a limited exemption for consumer products used the same way and about as often as a typical consumer would use them. If a worker uses a household cleaner occasionally the way someone would at home, the exemption may apply. But if the same product is used in higher volumes, more frequently, or in ways that raise exposure beyond consumer use, the exemption does not apply and an SDS is required. OSHA's 1910.1200(b)(6)(ix) describes the exception.

What information in an SDS tells you what fire extinguisher to use?

Section 5 (Fire-Fighting Measures) directly lists suitable extinguishing media and media that must not be used. Section 9 gives you the flash point and flammability limits that set the fire hazard class. Together, these two sections tell you whether a Class B extinguisher is needed for flammable liquids, whether water is prohibited due to reactivity, or whether CO2 or dry chemical is preferred. Always verify against your specific SDS rather than assuming by product category.

Are SDSs required for every chemical in the workplace, even small amounts?

OSHA's HazCom standard covers any hazardous chemical present in the workplace, with no de minimis quantity threshold. Even a single container of a hazardous solvent requires an SDS. The practical exceptions are the consumer product exemption and certain articles (solid materials in a fixed form that do not release hazardous substances during normal use). Quantity thresholds appear in EPA SARA 312 reporting rules, but not in OSHA's SDS requirement.

What does the signal word on an SDS mean?

Under GHS, two signal words are used: Danger and Warning. Danger indicates the more severe hazard category within a given hazard class. Warning indicates a less severe category. A product with no signal word has not been classified as presenting a GHS hazard under that classification. Signal words appear in Section 2 and on product labels. They give workers a fast severity cue before they read the full hazard and precautionary statements.

How long should you keep safety data sheets for chemicals you no longer use?

OSHA's 29 CFR 1910.1020 requires that employee exposure records, which include SDSs for chemicals workers were exposed to, be retained for 30 years from the date of last exposure. This is separate from the active-use accessibility requirement. If a chemical was used in your workplace and workers were exposed, keep the SDS for 30 years from the last day it was in use. Electronic storage makes this easy and cheap.

Can SDSs be stored electronically instead of in a paper binder?

Yes. OSHA explicitly allows electronic SDS management systems. The requirement is accessibility, not paper. Employees must be able to reach the SDS during their work shift without barriers. That means the system needs reliable hardware, backups during power outages, and workers trained to use it. A paper backup is a reasonable precaution if your electronic system can go down. OSHA has issued letters of interpretation confirming electronic systems are acceptable.

What is the CAS number on an SDS and why does it matter?

A CAS number is a unique Chemical Abstracts Service registry identifier assigned to every distinct chemical substance. It appears in Section 3 of the SDS. The CAS number is the most reliable way to look up independent toxicology data, cross-reference regulatory lists, and confirm you have the right chemical information. Searching by trade name or common name can return wrong or incomplete data; searching by CAS number is specific. NIOSH's Pocket Guide and NLM's toxicology databases both index by CAS number.

Sources

1. OSHA, 29 CFR 1910.1200 Hazard Communication Standard (via osha.gov/laws-regs): SDS 16-section requirement, trade secret provisions, manufacturer update obligation, written program and training requirements under HazCom
2. OSHA, Top 10 Most Frequently Cited Standards FY2023: Hazard communication was the second most frequently cited OSHA standard in FY2023, with 2,978 violations
3. OSHA, Appendix D to 29 CFR 1910.1200: Safety Data Sheets (via osha.gov/laws-regs): SDS sections 1 through 11 must be filled in; sections 12-15 must be present but OSHA does not enforce their accuracy
4. OSHA, Annotated PELs: OSHA acknowledges that NIOSH RELs and ACGIH TLVs may be more protective than OSHA PELs for some substances
5. NIOSH, Pocket Guide to Chemical Hazards: NIOSH Pocket Guide provides independent chemical hazard and exposure data indexed by CAS number
6. OSHA, Medical and First Aid (eyewash and emergency shower guidance): Emergency eyewash stations should deliver flushing fluid for at least 15 minutes, per the referenced ANSI/ISEA Z358.1 standard
7. NFPA, Codes and Standards (NFPA 30, Flammable and Combustible Liquids Code): Liquids with flash points below 100 degrees F are classified as flammable and require approved storage cabinets
8. EPA, Emergency Planning and Community Right-to-Know Act (EPCRA): SARA 312 Tier II reporting generally triggered at 10,000 pounds of hazardous chemical stored at one time, with lower thresholds for extremely hazardous substances
9. OSHA, 29 CFR 1910.1020 Access to Employee Exposure and Medical Records: Employee exposure records, including SDSs for chemicals workers were exposed to, must be retained for 30 years
10. National Library of Medicine, PubChem and toxicology resources: NLM toxicology databases provide data for chemicals indexed by CAS number, usable for independent verification of SDS data