Chemical hazard communication: the complete OSHA HazCom guide

Last updated 2026-07-09

What is chemical hazard communication under OSHA?

Chemical hazard communication, usually called HazCom, is OSHA's system for making sure workers know which hazardous chemicals they handle and what those chemicals can do to them. The rule lives at 29 CFR 1910.1200 for general industry, with parallel versions at 29 CFR 1926.59 for construction and 29 CFR 1915.99 for shipyards ^[1].

The idea is simple. Manufacturers and importers evaluate the hazards of every chemical they ship. They communicate those hazards through labels and Safety Data Sheets (SDSs). Employers then pass that information down to workers through training and container labeling. OSHA calls this the right-to-know, and it's been federal law since 1983.

In 2012, OSHA rebuilt HazCom to match the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS). The updated standard, fully enforceable on June 1, 2016, locked SDSs into 16 sections in a fixed order, required specific pictograms on labels, and tightened hazard classification criteria ^[2]. A second update in 2024 refined classification criteria and trade secret provisions ^[3].

HazCom is almost always the first or second most cited OSHA standard. In fiscal year 2023, OSHA cited it 3,213 times, second across all industries ^[4]. That's not because the rule is confusing. It's because a lot of employers treat it as paperwork instead of a working system.

Who does the HazCom standard apply to?

The standard applies to any employer whose employees may be exposed to hazardous chemicals under normal working conditions or in a foreseeable emergency ^[1]. That's a wide net on purpose.

A hair salon that uses chemical straighteners? Covered. A restaurant with commercial degreasers under the sink? Covered. A landscaping crew that sprays pesticides? Covered. Even an office that keeps correction fluid in a supply closet is technically covered if any employee might use it.

A few narrow exemptions exist. Hazardous waste covered by EPA rules, tobacco products, wood and wood products that have not been processed beyond sawing or splitting, FDA-regulated food and drugs used as intended by the employee, and retail food service operations are among the carve-outs ^[1]. Most workplaces with any cleaning, maintenance, or process chemicals sit squarely inside the rule.

Manufacturers and importers carry the heaviest load. They classify the hazards and produce the SDSs and labels. Distributors have to make sure SDSs travel with shipments. Employers downstream collect, maintain, and use the information those upstream parties send, then add their own training and labeling on top.

If you thought HazCom only touched factories or chemical plants, look again. OSHA's letters of interpretation have consistently confirmed that the standard reaches wherever workers encounter chemicals, including service industries and offices ^[1].

What must a written HazCom program include?

Every covered employer needs a written HazCom program, and it has to be available to employees, their representatives, and OSHA inspectors during any workday ^[1]. You can't lock it in a manager's office.

At a minimum, the written program has to address five things:

1. How your workplace labels containers (both incoming shipped containers and any containers you fill or transfer chemicals into) 2. How you maintain your collection of SDSs and keep them reachable during every shift 3. How you provide employee information and training 4. A list of the hazardous chemicals in each work area (tied to the SDSs you keep) 5. How you handle non-routine tasks and multi-employer worksites, if those apply

The chemical list is the first thing inspectors check. It doesn't have to be fancy. A spreadsheet or a plain written list works. But it has to exist and be current. Chemicals you phased out come off the list. New chemicals go on before workers start using them.

Multi-employer worksites get a little more detailed. If contractors or subs work on your site, you have to tell them which hazardous chemicals they might be exposed to, and they share the same information back about theirs ^[1]. A construction general contractor managing several subs has to plan for this.

If you need a program fast and don't want to start from a blank page, SafetyFolio's safety program generator builds a customized HazCom program in about 15 minutes by walking you through your specific chemicals and work areas.

One honest note. OSHA does not require any particular template. A one-page document covering all five elements above is legally enough for a small business with simple chemical use. Buying a 40-page template from a consultant when you run a three-person shop is money wasted.

What are the GHS label requirements for chemical containers?

Every container of a hazardous chemical in your workplace has to be labeled. OSHA sets six required elements for labels on shipped containers ^[1]:

• Product identifier (the chemical name or code that ties the label to the SDS)
• Signal word ("Danger" for more severe hazards, "Warning" for less severe)
• Hazard statement(s) describing the nature and degree of the hazard
• Precautionary statement(s) covering prevention, response, storage, and disposal
• Pictogram(s), the GHS symbols inside a red diamond border
• Supplier identification (name, address, and phone number of the manufacturer or importer)

There are nine GHS pictograms in all. They cover categories like flammable (flame), corrosive (corroding surface), acute toxicity (skull and crossbones), and health hazard (the silhouette with a starburst on the chest) ^[11].

Workplace containers, meaning containers you fill, transfer chemicals into, or label yourself, get a little more flexibility. You still need a product identifier plus words, pictures, or symbols that give information about the hazards ^[1]. A handwritten label reading "Acetone, flammable, keep away from ignition sources" on an in-house transfer container satisfies the rule. OSHA's letters of interpretation confirm employers have discretion on secondary containers, as long as the hazard information is there ^[1].

You cannot remove or deface the label on an incoming container. If a drum arrives labeled, that label stays until the container is empty and cleaned.

Pipes and piping systems, vehicles, and some other conveyances have alternative labeling options under the standard. Check 29 CFR 1910.1200(f)(7) for those provisions.

What is a Safety Data Sheet and what does each section cover?

A Safety Data Sheet is the detailed hazard and handling document that manufacturers and importers create for each hazardous chemical they produce. Since the 2012 GHS update, every SDS follows a 16-section format in a fixed order ^[1]. That standardization pays off. Once you know the format, you can find what you need on any SDS from any supplier.

Here's what each section covers:

Section	Title	What's in it
1	Identification	Product name, recommended uses, supplier contact
2	Hazard(s) identification	GHS classification, signal word, pictograms, hazard statements
3	Composition/ingredients	Chemical identity, CAS numbers, trade secret info if applicable
4	First-aid measures	What to do after exposure
5	Fire-fighting measures	Suitable extinguishing media, special hazards
6	Accidental release measures	Spill cleanup and containment procedures
7	Handling and storage	Safe handling practices, storage conditions
8	Exposure controls/PPE	OSHA PELs, ACGIH TLVs, required protective equipment
9	Physical and chemical properties	Flash point, boiling point, vapor pressure, etc.
10	Stability and reactivity	Incompatible materials, hazardous decomposition products
11	Toxicological information	Routes of exposure, acute and chronic health effects
12	Ecological information	Environmental impact (not enforced by OSHA)
13	Disposal considerations	Waste disposal methods
14	Transport information	DOT/IATA/IMDG classification
15	Regulatory information	Other regulations that apply
16	Other information	Date of latest revision, changes

Section 8 matters most to daily work. That's where you find the Permissible Exposure Limits (PELs), OSHA's legally enforceable limits on airborne chemical concentrations, plus the recommended personal protective equipment. Trying to figure out whether workers need respirators or specific gloves for a chemical? Start there.

You can see a real example of a well-built SDS in the hcl safety data sheet for hydrochloric acid, which shows how all 16 sections play out in practice.

Employers have to keep SDSs for every hazardous chemical in the workplace. OSHA requires them to be accessible to employees in their work area during every shift ^[1]. Electronic SDS systems are fine. You just need a backup plan for power outages or system failures, and workers need to reach the system without asking a supervisor for help.

What HazCom training must employers provide?

Training is where a lot of employers fall short. The rule at 29 CFR 1910.1200(h) requires training before initial assignment to any work area where hazardous chemicals are present, and again whenever a new hazard is introduced into the area ^[1]. "Before initial assignment" means before the worker's first day in that area, not at the end of their first week.

Training has to cover:

• Where the written HazCom program is kept and how to reach it
• How to read and use SDSs
• How to read GHS-format labels
• The location and availability of the hazard list
• The physical and health hazards of the specific chemicals in the work area
• How employees protect themselves (engineering controls, work practices, PPE)
• What to do in an emergency

A few things training does not have to be. It doesn't need to be classroom instruction. It doesn't need to run a set number of hours. It doesn't need a certified trainer. Online modules, toolbox talks, one-on-one walkthroughs with a supervisor, or any mix all work. What matters is that employees actually understand it afterward.

OSHA says training must be "in a language and vocabulary that employees can understand" ^[1]. If some of your workers speak a primary language other than English, English-only training probably doesn't meet the rule. OSHA has cited employers on exactly this point.

You also have to document training. The regulation names no required format, but if OSHA shows up and asks whether workers were trained before they touched a chemical, "yes" with nothing to show is a weak answer. Keep a sign-in sheet, a quiz, or a supervisor's written attestation.

For how OSHA's training duties stack up across your whole program, the osha training guide covers the full picture.

How does OSHA classify chemical hazards under GHS?

GHS splits chemical hazards into two main groups: physical hazards and health hazards. Manufacturers and importers classify their chemicals into specific hazard classes and categories within those classes ^[1].

Physical hazard classes include flammables (liquids, solids, gases, aerosols), explosives, oxidizers, compressed gases, self-reactive substances, pyrophorics, and several others. Each class has categories (usually 1 through 4, with 1 the most hazardous) that decide which signal word and hazard statements land on the label.

Health hazard classes cover acute toxicity (split by route: oral, dermal, inhalation), skin corrosion and irritation, serious eye damage and irritation, respiratory or skin sensitization, germ cell mutagenicity, carcinogenicity, reproductive toxicity, specific target organ toxicity (STOT) for both single and repeated exposure, and aspiration hazard.

There's also an environmental hazard group (aquatic toxicity) in the GHS framework, but OSHA does not enforce it. It shows up in SDS section 12 because many suppliers use international GHS formats. It's outside OSHA's HazCom rule.

The classification work is scientific and can get genuinely complex for chemical makers. Employers don't classify chemicals themselves. You rely on the SDS that comes with the product. Your job is to make sure that SDS exists, that it's current, and that your workers understand what the classifications mean for handling the chemical day-to-day.

What are the OSHA penalties for HazCom violations?

OSHA raises its maximum penalties every year for inflation. As of 2024, a serious HazCom violation carries a maximum of $16,131 per violation, and a willful or repeated violation can reach $161,323 per violation ^[6].

Most citations come with lower proposed penalties after OSHA applies its adjustment factors for employer size, good faith, and history. A small employer with fewer than 25 workers can earn up to a 60 percent cut from the base penalty ^[6]. Even so, it adds up fast when you have several citations, and HazCom citations often group. Missing SDSs for ten chemicals can become ten separate violations.

The HazCom violations OSHA cites most often are ^[4]:

1. No written HazCom program at all 2. Missing or incomplete SDSs 3. Inadequate or missing employee training (no documentation) 4. Improper labeling of workplace containers 5. Employees who can't locate SDSs or the written program

All five are easy to fix before an inspection. OSHA runs a no-cost, confidential On-Site Consultation Program where a state consultant visits your workplace, identifies hazards, and gives you time to fix them before any enforcement ^[10]. It's genuinely useful for small employers, and taking part doesn't trigger an inspection.

Get cited and you have 15 working days to contest. The informal settlement conference with your OSHA area director is usually the best first move. Many penalties drop significantly there.

How should employers handle trade secrets in HazCom?

A chemical manufacturer can withhold the specific chemical identity of a substance from an SDS if that identity qualifies as a trade secret, meaning it gives a competitive advantage and isn't generally known ^[1]. This is one of the more nuanced corners of HazCom.

Withholding the identity does not mean withholding safety information. OSHA's rule at 29 CFR 1910.1200(i) requires that even a trade secret SDS disclose all health effects, exposure limits, precautions, and emergency information for the substance. The only thing that can hide is the specific chemical name.

Even that protection has limits. The standard says that in a medical emergency, a manufacturer "shall immediately disclose the specific chemical identity of a trade secret chemical" to treating medical personnel ^[1]. No confidentiality agreement required when someone's in the ER.

Outside emergencies, a health professional, industrial hygienist, or nurse who needs the chemical identity for a medical or occupational health reason can request it in writing, explain why, and agree to keep it confidential. The manufacturer then has to provide it.

As an employer, your practical job is to make sure any SDS you hold with a trade secret claim still gives workers enough to protect themselves. If an SDS is so vague it won't tell you what PPE to wear or what to do in a spill, push back on your supplier. That's a real gap, not a formality.

How do you maintain SDS records and keep them accessible?

OSHA's rule says SDSs must be readily accessible to employees in their work area during each work shift ^[1]. OSHA has read that phrase consistently. If a worker needs an SDS and something slows them down, you probably don't meet the standard.

A physical binder in each work area is the simplest fix and still common in manufacturing and warehouses. The tradeoff is keeping it current as suppliers revise their SDSs, which they're supposed to do whenever significant new hazard information turns up.

Electronic SDS systems, whether software or a cloud service, are accepted by OSHA as long as ^[1]:

• Employees know how to use the system
• The system is reachable from the work area, not only from an office computer
• There's a backup procedure when the system is down

That backup procedure is something inspectors ask about. "We'd call someone" is not a backup procedure. A printed set of SDSs for your most hazardous chemicals kept on the floor is a reasonable one.

You don't technically have to keep SDSs for chemicals you no longer use. But OSHA's medical records rule (29 CFR 1910.1020) requires exposure records, which include SDSs when they were used to characterize employee exposures, to be kept for 30 years after a worker leaves ^[7]. In practice, many safety pros just keep SDSs indefinitely for chemicals used while employees were present.

For a chemical that arrives without an SDS, you have to contact the manufacturer and get one. Document that you tried. Keep the request on file. "The supplier didn't send one" doesn't move your legal obligation anywhere.

What are the special HazCom rules for construction sites?

Construction falls under 29 CFR 1926.59, which mirrors the general industry standard almost line for line. The requirements for written programs, SDSs, labels, and training are essentially the same ^[8].

The main practical difference is the multi-employer environment. On a typical site, several contractors bring chemicals onto the same project. The general contractor has to set up a way to pass hazard information among every employer on site, more than manage their own workers' exposures. That usually means a site-wide chemical inventory log, a shared SDS location or system, and a kickoff briefing to all subs when the project starts.

Foreman-to-worker communication on job sites deserves real thought too. Crews rotate between projects and meet a different set of chemicals on each one. Training that teaches "here's how to read an SDS" is the foundation, but site-specific briefings when new chemicals arrive matter just as much.

OSHA's construction HazCom standard carries the same exemptions for certain wood products and the same training-language requirement as general industry. If you're a construction contractor mapping your wider OSHA duties, the lockout tagout guide covers another standard that shows up alongside HazCom on job sites.

How do you build a practical HazCom program from scratch?

Here's the sequence that actually works for a small or mid-size employer.

Step 1: Walk the whole facility and write down every chemical product present. Include cleaning supplies, lubricants, paints, compressed gases, fuels, and anything in maintenance storage. This is your chemical inventory. It becomes the list referenced in your written program.

Step 2: Request SDSs for anything that doesn't have one. Most suppliers post them on their websites now. If you can't find one online and the supplier goes quiet, document your attempts.

Step 3: Write the program document. It has to cover your labeling approach, your SDS system, your training process, and your chemical list. Three to five pages is plenty for a company with straightforward chemical use. Rather not write it yourself? SafetyFolio generates a site-specific written program in about 15 minutes based on your actual chemicals and work areas.

Step 4: Set up SDS access. Physical binder, electronic system, or both. Train every employee on how to use it before they work with any hazardous chemical.

Step 5: Train employees. Cover labels, SDSs, the specific chemicals they'll use, and what to do in an emergency. Document it.

Step 6: Check container labels. Incoming containers should already be labeled by the supplier. Anything you fill or transfer into gets a workplace label.

Step 7: Build a maintenance habit. New chemical comes in? Update the inventory, get the SDS, brief the affected workers. Quarterly inventory reviews catch drift before an inspector does.

The whole thing isn't hard. HazCom stays at the top of OSHA's citation list because employers start the program and then stop maintaining it. A stale SDS binder from 2019 with no new additions is a citation waiting to happen.

How does HazCom connect to other OSHA standards?

HazCom doesn't run alone. It's the foundation layer, and several other OSHA standards build on it or overlap with it.

The Respiratory Protection standard (29 CFR 1910.134) leans on HazCom because SDS section 8 spells out what respiratory protection a chemical needs ^[12]. If your HazCom program is incomplete, you may not even know which chemicals demand a respirator program.

PPE standards (29 CFR 1910.132 through 1910.140) connect the same way. Glove selection, eye protection, and protective clothing decisions all trace back to the chemical hazard information in SDSs. The PPE standard requires a hazard assessment, and chemical SDSs feed that assessment.

Process Safety Management (29 CFR 1910.119) applies to facilities holding highly hazardous chemicals above set threshold quantities ^[9]. HazCom is a prerequisite. Without your chemical inventory and SDSs organized, you can't tell whether you cross PSM thresholds.

OSHA's substance-specific standards, like the lead standard (29 CFR 1910.1025), the benzene standard (29 CFR 1910.1028), and the formaldehyde standard (29 CFR 1910.1048), carry tighter requirements than HazCom for those particular chemicals. HazCom still applies to them too. The specific standard adds to it; it doesn't replace it ^[1].

Trying to see how all of OSHA's requirements fit together? Get HazCom right first. It forces you to inventory your chemicals, which is useful input for nearly every other safety program you need.

Frequently asked questions

Does a small business with only a few cleaning products need a full HazCom program?

Yes. The threshold isn't quantity, it's whether any employee may be exposed to a hazardous chemical. Common cleaning products like bleach-based cleaners and degreasers qualify. A small business's written program and SDS binder can be simple, maybe two pages and a handful of SDSs, but they must exist and stay accessible to employees during every shift per 29 CFR 1910.1200.

How often do SDSs need to be updated?

Manufacturers must update SDSs when significant new hazard information surfaces, then send updated sheets to distributors within three months of learning about the change. There's no fixed calendar requirement. As an employer, verify your SDSs match the current version from your supplier, especially after a formula revision. Periodic reviews, annually or when you renegotiate supplier contracts, are a reasonable habit.

Can we keep our SDSs online or in a computer instead of a paper binder?

Yes, electronic SDS systems are acceptable under 29 CFR 1910.1200. OSHA requires that employees know how to use the system, that it's reachable from the work area during every shift, and that a reliable backup exists when it goes down from a power outage or technical failure. A printed backup set of SDSs for your most hazardous chemicals is the simplest contingency.

What happens if we receive a chemical without a Safety Data Sheet?

You're responsible for getting one. Contact the manufacturer or importer immediately and document the request in writing. OSHA won't let "the supplier didn't send it" satisfy your obligation. If you can't obtain an SDS after reasonable documented attempts, you may need to restrict use of that chemical until one arrives. Keep your documentation of requests on file for an inspection.

Are there chemicals that are exempt from the HazCom standard?

Yes, but fewer than most employers assume. Exempted materials include hazardous waste regulated by EPA under RCRA, tobacco products, wood and wood products processed only by sawing or splitting, FDA-regulated foods and drugs used as intended by employees, and a few others listed at 29 CFR 1910.1200(b)(6). Most workplace chemicals, including common cleaners, fuels, lubricants, and adhesives, are covered.

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

A Permissible Exposure Limit (PEL) is OSHA's legally enforceable cap on airborne chemical concentration, expressed as a time-weighted average over an 8-hour shift. A Threshold Limit Value (TLV) comes from ACGIH (American Conference of Governmental Industrial Hygienists) and is not legally enforceable, though it's often more current and health-protective than OSHA's PELs, many of which date to 1971. Both appear in SDS Section 8. OSHA inspectors cite against PELs.

How specific does HazCom training have to be?

Training must cover the chemicals in that employee's specific work area, not generic HazCom concepts alone. A worker handling three chemicals needs training on those three chemicals' hazards, required PPE, spill and emergency response, and how to read their labels and SDSs. OSHA has cited employers whose training was entirely generic with no reference to the chemicals workers actually used. Document it with a sign-in sheet and the topics covered.

Do we need to retrain employees every year?

No. There is no annual retraining requirement under 29 CFR 1910.1200. The triggers are initial assignment to a new work area with hazardous chemicals, and introduction of a new hazard into an existing work area. If neither happens, you don't have to repeat training. That said, periodic refreshers when your chemical inventory changes or after a chemical exposure incident are good practice.

What do GHS pictograms mean, and do workers have to memorize them?

GHS uses nine standardized pictograms in red diamond borders: flame (flammable), flame over circle (oxidizer), exploding bomb (explosive), gas cylinder (compressed gas), skull and crossbones (acute toxicity), exclamation mark (irritant/less severe hazard), health hazard silhouette (carcinogen, sensitizer, STOT), corrosion (skin/eye damage), and environment (aquatic toxicity, not OSHA-enforced). Workers don't need to memorize them cold, but training must make sure they understand what each symbol means for the chemicals they use.

What is a multi-employer worksite obligation under HazCom?

When several employers share a worksite, each one must make sure its workers know about hazardous chemicals brought on site by others. In practice, the host employer keeps a site chemical inventory, provides SDS access to all contractors, and flags any site-specific hazards. Contractors return the favor by informing the host of hazardous chemicals they're bringing in. This is required under 29 CFR 1910.1200(e)(2).

How does the 2024 HazCom update change what employers need to do?

OSHA's 2024 revision (published in May 2024) updated classification criteria for some hazard categories, revised requirements for certain aerosol products, and clarified trade secret provisions. For most small employers the impact is minor: review your SDS collection for chemicals in the affected categories (particularly aerosols and certain flammables) to see if suppliers revised their sheets, and update program language if you cite specific classification criteria. Compliance dates are phased, with manufacturers having until January 2026 for updated labels ^[3].

Can employees refuse to work with a chemical if they don't have an SDS for it?

HazCom gives employees the right to hazard information before working with chemicals. It doesn't create an explicit right to refuse, but employees who reasonably believe they face imminent danger may have protection under Section 11(c) of the OSH Act. More directly, if you can't produce an SDS you're violating 1910.1200 and inviting a citation. Practically, get the SDS before assigning the work.

Does HazCom apply to pesticides used in agricultural operations?

Agricultural pesticides are regulated by EPA under FIFRA (Federal Insecticide, Fungicide, and Rodenticide Act), not OSHA's HazCom standard, when used in farm operations. Pesticides used in non-agricultural settings, such as a pest control company or a janitorial service, are covered by HazCom. The line is the agricultural application context, not the chemical itself.

What's the best way to organize SDSs for a workplace with hundreds of chemicals?

Alphabetical by product name is simplest where workers know their chemical names. A searchable electronic system works well at scale. Either way, the organizing principle matters less than whether employees can find the right SDS within seconds without supervisor help. OSHA's test during an inspection is often to ask a random worker how they'd pull the SDS for a specific chemical they use. Organize to pass that test.

Sources

1. OSHA, Hazard Communication Standard 29 CFR 1910.1200: Full text of HazCom requirements: written program, SDS, labeling, training, applicability, and trade secrets
2. OSHA, Hazard Communication: GHS Overview: 2012 GHS alignment update standardized 16-section SDS format and GHS pictogram requirements; full enforcement effective June 1, 2016
3. OSHA, Hazard Communication Standard Final Rule 2024 (Federal Register summary): 2024 HazCom update revised classification criteria for aerosols and other categories; manufacturers have until January 2026 for updated labels
4. OSHA, Top 10 Most Frequently Cited Standards FY 2023: Hazard Communication (29 CFR 1910.1200) was cited 3,213 times in FY 2023, the second most-cited OSHA standard
5. OSHA, Penalties (annual inflation adjustment): As of 2024: serious violations up to $16,131 per violation; willful or repeated violations up to $161,323; small employers (under 25 workers) eligible for up to 60 percent reduction
6. OSHA, Access to Employee Exposure and Medical Records, 29 CFR 1910.1020: Exposure records, including SDSs used to characterize exposure, must be retained for 30 years after an employee leaves employment
7. OSHA, Construction Hazard Communication 29 CFR 1926.59: Construction HazCom standard mirrors general industry requirements for written programs, SDSs, labeling, and training
8. OSHA, Process Safety Management of Highly Hazardous Chemicals, 29 CFR 1910.119: PSM applies above threshold quantities of highly hazardous chemicals; HazCom applies concurrently and does not replace PSM requirements
9. OSHA On-Site Consultation Program: Free, confidential on-site consultation available to small employers; participation does not trigger enforcement inspections
10. United Nations, Globally Harmonized System of Classification and Labelling of Chemicals (GHS), 10th revised edition: GHS defines nine standard pictograms and two signal words (Danger, Warning); physical and health hazard classification criteria
11. OSHA, Respiratory Protection Standard, 29 CFR 1910.134: Respiratory protection requirements connect to SDS Section 8 information; chemical exposure data from SDSs informs respirator selection