Globally harmonized hazard communication standard: what it means for your workplace

Last updated 2026-07-09

What is the globally harmonized system for hazard communication?

The Globally Harmonized System of Classification and Labelling of Chemicals, usually called GHS, is a United Nations framework that gives the world one set of rules for deciding how dangerous a chemical is and how to warn workers and emergency responders about it. Before GHS, a drum of sulfuric acid might carry one set of warnings in the United States, a completely different set in Europe, and yet another in Japan. That inconsistency killed people.

The UN published the first edition of the GHS in 2003, sometimes called the "Purple Book." ^[1] It covers three things: hazard classification criteria, label elements (signal words, pictograms, hazard statements, precautionary statements), and a standardized Safety Data Sheet format. Countries and trade blocs adopt GHS through their own regulations, so the underlying UN document is a model, not a binding law by itself.

OSHA is the agency that made GHS legally binding for most U.S. workplaces. OSHA's rule is the Hazard Communication Standard at 29 CFR 1910.1200, usually called HazCom. The 2012 revision of HazCom aligned it with the third revised edition of GHS and set the compliance dates most employers remember. A later final rule published in May 2024, commonly called HazCom 2024, aligned the standard with GHS Revision 7 and added several new hazard classes. ^[2]

GHS matters to you for a simple reason. It defines every label on every chemical product you buy, and it sets the format of every Safety Data Sheet your workers read. Get it wrong and you land on the list of OSHA's most-cited violations, year after year.

Why did OSHA adopt GHS into the HazCom standard?

The old HazCom standard, in place since 1983, let chemical manufacturers write Material Safety Data Sheets in almost any format they chose. Some had 8 sections, some had 16, some buried flash point data in a footnote. Workers couldn't find what they needed fast enough, and companies doing business internationally had to produce separate documents for each country's format.

OSHA estimated that aligning with GHS would save about $585 million per year in reduced chemical-related injuries and illnesses, based on the 2012 rulemaking's regulatory impact analysis. ^[3] The agency also projected that the standardized SDS format alone would save U.S. businesses roughly $752 million by ending the need to reconcile conflicting international requirements. ^[3]

Those figures are projections, not measured outcomes, so treat them with the skepticism any projection deserves. What's not in dispute: HazCom sits near the top of OSHA's most-cited standards. In fiscal year 2023, it was the second most-cited standard, with more than 3,000 violations issued. ^[4] Most of those citations trace to missing or outdated SDSs, incomplete labels, and thin employee training. All things GHS was supposed to fix.

Trade drove the change too. The European Union put its version of GHS (called CLP, the Classification, Labelling and Packaging Regulation) into effect in 2008. ^[9] Canada rolled out WHMIS 2015 around the same period. U.S. manufacturers exporting chemicals were already producing GHS-compliant documents for foreign customers. Matching the domestic rule cut the duplication.

How does GHS chemical classification work?

GHS classification is the starting point. A chemical manufacturer or importer looks at a chemical's properties, runs them against defined criteria, and assigns the chemical to a hazard class and a category within that class. The category number signals severity, with Category 1 being the most severe in most (though not all) hazard classes.

GHS sorts hazards into two broad groups: physical hazards and health hazards, plus a group for environmental hazards. OSHA does not regulate the environmental group under HazCom, since EPA handles environmental labeling. ^[2]

Physical hazard classes include flammable liquids, explosives, oxidizers, and gases under pressure. Health hazard classes cover acute toxicity, skin corrosion and irritation, serious eye damage, respiratory or skin sensitization, carcinogenicity, reproductive toxicity, and specific target organ toxicity, among others.

HazCom 2024 revised or added criteria for several physical hazard classes, including flammable gases and desensitized explosives, and it split aerosols into flammable and non-flammable categories. ^[2] It also expanded reproductive toxicity to cover effects on or via lactation, and it addressed endocrine disruptors under a new framework. If you're updating your written HazCom program, check whether any of your chemicals now fall into the new classes.

Manufacturers and importers own the classification job. Downstream employers, the ones buying and using chemicals, generally don't reclassify. But you are on the hook for keeping your SDSs current and for making sure your labels match what the SDS says.

What are the nine GHS pictograms and when do you see each one?

GHS uses nine standardized pictograms: black symbols inside a red diamond border. Each one maps to specific hazard classes. Here's the plain-language breakdown:

Pictogram	Symbol description	Key hazard classes
Flame	Flame	Flammable liquids, solids, gases; self-reactive substances; pyrophorics
Flame over circle	Flame above a circle	Oxidizers
Exploding bomb	Bomb with explosion	Explosives, self-reactive, organic peroxides
Skull and crossbones	Skull and crossbones	Acute toxicity (severe), Categories 1-3
Exclamation mark	Bold exclamation point	Acute toxicity (less severe, Cat 4), irritants, sensitizers, harmful substances
Corrosion	Liquid dripping on hand and surface	Skin/eye corrosion, metals corrosion
Health hazard	Torso with starburst	Carcinogens, reproductive toxins, specific organ toxins, respiratory sensitizers
Gas cylinder	Pressurized cylinder	Gases under pressure
Environment	Dead tree and fish	Aquatic toxicity (not currently required by OSHA HazCom)

The exclamation mark and the health hazard diamond trip people up most often. The exclamation mark covers "less severe" effects like skin irritation, which are still serious. The health hazard diamond (the torso with a starburst) covers long-term or systemic effects like carcinogenicity. A single chemical can carry several pictograms at once.

Pictograms must appear on shipped container labels and on the SDS. Workplace labels for secondary containers (ones you fill from a larger container) have to show the chemical identity, hazard pictograms, and hazard statements. You can substitute an alternative system, such as a numbering scheme, as long as workers are trained on it and the information stays immediately available. ^[5]

Want the official graphic files? OSHA publishes them on its HazCom page. ^[5] Don't pull pictograms from random image searches. Use the official files so you don't botch the border shape or a symbol detail.

What are the 16 sections of a GHS Safety Data Sheet?

Every SDS produced under GHS follows the same 16-section order. That standardization is the whole point. A worker or emergency responder who knows the format finds first aid measures in Section 4 and firefighting measures in Section 5 without reading the whole document.

Here are all 16 sections and what each one holds:

Section 1, Identification: product name, manufacturer contact, recommended use, emergency phone number. Section 2, Hazard identification: GHS classification, label elements, signal word, hazard statements, pictograms. Section 3, Composition/ingredients: chemical identity, CAS numbers, concentration or concentration ranges, trade secret claims if any. Section 4, First aid measures: by exposure route (inhalation, skin, eyes, ingestion), symptoms, when to seek medical attention. Section 5, Firefighting measures: suitable extinguishing media, specific hazards from combustion, protective equipment for firefighters. Section 6, Accidental release measures: personal precautions, environmental precautions, containment and cleanup methods. Section 7, Handling and storage: safe handling practices, storage conditions, incompatible materials. Section 8, Exposure controls/personal protection: OSHA PELs, ACGIH TLVs, engineering controls, PPE requirements. Section 9, Physical and chemical properties: appearance, odor, flash point, boiling point, vapor pressure, solubility, and similar properties. Section 10, Stability and reactivity: chemical stability, conditions to avoid, hazardous decomposition products. Section 11, Toxicological information: routes of exposure, acute and chronic effects, numerical toxicity data (LD50, LC50). Section 12, Ecological information: environmental fate, toxicity to aquatic organisms (required by GHS, not currently enforced by OSHA). Section 13, Disposal considerations: waste disposal methods, regulatory requirements. Section 14, Transport information: DOT, IATA, IMDG classification, UN number, packing group. Section 15, Regulatory information: other regulations that apply (TSCA, state right-to-know laws, CERCLA reportable quantities). Section 16, Other information: revision date, changes from previous version, disclaimer.

Section 8 is the one your workers reach for day to day. That's where they learn whether they need a respirator and what type, which gloves to use, and what engineering controls (ventilation, enclosure) the chemical demands. If an SDS lists a permissible exposure limit, cross-check it against the current OSHA PEL table. Some SDSs still cite outdated PEL values. ^[6]

For a worked example of a real SDS, the HCl safety data sheet is a good concrete reference. Hydrochloric acid triggers multiple GHS hazard classes, so its SDS shows how sections 2, 4, and 8 fit together.

What does a GHS-compliant label require?

A shipped container label under 29 CFR 1910.1200 must carry six elements: the product identifier, signal word, hazard statement(s), precautionary statement(s), pictogram(s), and the supplier's name and contact information. ^[5] Every one is mandatory. Miss even one and you have a citable violation.

The signal word is either "Danger" or "Warning." Danger applies to more severe hazard categories, Warning to less severe. A label never carries both. If a chemical has two hazard classes where one warrants Danger and one warrants Warning, only Danger appears on the label.

Hazard statements describe the nature of the hazard, for example "Causes serious eye damage" or "May cause cancer." Precautionary statements tell people what to do: prevention ("Do not breathe vapors"), response ("If in eyes: rinse cautiously with water for several minutes"), storage ("Store locked up"), and disposal ("Dispose of contents in accordance with local regulations"). You can't write your own. GHS assigns standardized H-codes (hazard) and P-codes (precautionary) to each class and category. ^[1]

Label size matters too. OSHA sets minimum label element sizes by container volume. Containers of 100 mL or less have smaller minimums than drums of 100 gallons or more. The pictogram border must be red (not black, not blue) on shipped containers. Workplace secondary container labels get more flexibility but still have to stay legible and durable. ^[5]

Here's a mistake small employers make: they assume a product's existing consumer label satisfies HazCom. It usually doesn't. Consumer labels answer to the Consumer Product Safety Commission and don't follow the GHS label element structure. If a consumer product is used at work in a way that creates a hazard, it needs a proper SDS and may need a compliant workplace label.

What are the HazCom 2024 changes and when do employers have to comply?

OSHA published the HazCom 2024 final rule on May 20, 2024. ^[2] The rule changed several employer obligations.

New hazard classes: Three physical hazard classes got revised or added criteria (flammable gases, aerosols split into flammable and non-flammable categories, desensitized explosives). New health hazard coverage arrived too, including hazards to the aquatic environment (informational, not enforced by OSHA), hazards to the ozone layer, and the change many industries care about, reproductive toxicity expanded to include effects on or via lactation. Endocrine disruptors fall under a new "hazards not otherwise classified" framework.

Updated SDS and label requirements: Manufacturers and importers must reclassify chemicals that fall into the new categories and update their SDSs and labels to match.

Compliance deadlines under HazCom 2024 are staggered:

Who	Deadline
Chemical manufacturers and importers (update SDSs/labels for new classes)	July 19, 2026
Distributors (ship only compliant labels)	January 19, 2027
Employers (update written HazCom programs, train workers on new elements)	July 19, 2027

Those dates come from the 2024 final rule. ^[2] If you rely on a consultant or a software-generated program, confirm they've built in the 2024 updates. Plenty of template programs still circulating online reflect only the 2012 rule.

If you run a lean compliance team, start now. Request updated SDSs from your chemical suppliers as they publish revised versions, refresh your SDS binder or digital system, and put a training update on the calendar before mid-2027.

What must a written HazCom program include under 29 CFR 1910.1200?

The Hazard Communication Standard requires every employer to have a written hazard communication program. ^[5] It's not optional, and a poster or a binder of SDSs alone doesn't cover it. The written program has to describe how your specific workplace handles each element of the standard.

At minimum, a compliant written HazCom program addresses:

1. Container labeling: how labels are maintained, what happens when a label is damaged or missing, and what system you use for secondary (workplace-filled) containers. 2. Safety Data Sheets: where SDSs are kept, how workers access them on all shifts, and how you obtain SDSs for new chemicals before they're introduced. 3. Employee training: what training covers, when it happens (before initial assignment to a hazardous chemical, not afterward), and who delivers it. 4. The list of hazardous chemicals in the workplace: a chemical inventory that cross-references each chemical to its SDS. 5. Methods for informing workers about unlabeled pipes and non-routine tasks involving hazardous chemicals.

Got contractors on-site? You have to tell them where your SDSs are and make those SDSs available. And when your workers go into another employer's workplace, you have to hand that employer the SDSs for any hazardous chemicals your workers bring with them. ^[5]

Building this program from scratch takes most small business owners several hours, and the chemical inventory eats most of that time. A tool like SafetyFolio's safety program generator cuts the drafting time by walking you through each required element and producing a program document you can customize. The inventory is still yours to do, because nobody outside your workplace knows what chemicals you actually keep.

For the training side specifically, the OSHA training overview breaks down what counts as compliant initial training versus refreshers.

What HazCom training do workers need?

Training is where employers cut corners and get cited. The standard says training must happen "at the time of initial assignment" to work with hazardous chemicals, and again when a new hazard enters the workplace. ^[5] It doesn't say annually, though refreshing training when the hazard picture shifts is good practice and required when new chemicals arrive.

Training must cover:

• The requirements of the HazCom standard itself (what the law demands).
• Operations in the employee's work area where hazardous chemicals are present.
• Where the written HazCom program, the chemical inventory, and SDSs live, and how to reach them.
• How to detect the presence or release of a hazardous chemical (visual appearance, odor, monitoring equipment).
• Physical and health hazards of the chemicals in the work area.
• Protective measures: appropriate PPE, safe work practices, emergency procedures.
• How to read and understand labels and SDSs.

There's no OSHA-specified number of training hours for HazCom. The standard describes what must be covered, not how long it takes. OSHA has issued letters of interpretation making clear that a 5-minute handout doesn't satisfy the requirement if it fails to cover the listed topics. ^[7]

Language is a real problem in a lot of workplaces. OSHA's position, confirmed in multiple letters of interpretation, is that training must run in a language and vocabulary workers can understand. ^[7] If your workforce includes people whose primary language isn't English, the training has to be in their language. An English-only video and a hope for the best is not compliant.

For a wider view of training across OSHA standards, the OSHA 30 course covers HazCom as one module, which gives supervisors and safety leads a working grasp of the standard in context.

How do GHS requirements differ between the US, EU, and Canada?

GHS is a model system, not a treaty. Each jurisdiction implements it differently, and those differences matter if you import, export, or move workers between countries.

The United States (OSHA HazCom): Aligned with GHS Revision 7 as of 2024. Covers physical and health hazards. The environmental hazard class (Section 12 of the SDS) is informational only; EPA, not OSHA, regulates environmental labeling. Consumer products used as intended in a household context are exempt.

The European Union (CLP Regulation): Based on GHS but with real deviations. The EU keeps its own classification list (the CLP Annex VI harmonized table), which takes precedence over manufacturer self-classification for listed substances. The EU requires environmental hazard classification in most product categories. ^[9] CLP also uses slightly different hazard category cutoffs than OSHA in some classes.

Canada (WHMIS 2015): Aligned with GHS but keeps some Canada-specific requirements, including bilingual (English and French) labels for products sold in Canada and "Safety Data Sheet" spelled out in both languages. Canada also runs a supplier confidential business information protection regime that differs from OSHA's trade secret provisions.

If you're a small U.S. employer buying chemicals domestically and not exporting, most of these differences don't touch you. They start to matter when you read an SDS originally written for a European or Canadian market, where some hazard classifications may differ from a U.S.-authored version. If a chemical is a carcinogen in the EU but not in the U.S., that's worth knowing even when OSHA doesn't require you to act on the EU call.

Jurisdiction	Regulation name	GHS edition basis	Env. hazards required?
USA	HazCom (29 CFR 1910.1200)	GHS Rev. 7 (2024 rule)	No (informational)
EU	CLP (EC 1272/2008)	GHS Rev. 10 (current)	Yes
Canada	WHMIS 2015	GHS Rev. 5	Limited
Japan	JIS Z 7253	GHS Rev. 8	Partial

What do OSHA citations look like for HazCom violations, and what do they cost?

HazCom lives in OSHA's top-ten most-cited standards nearly every year. In FY2023, OSHA issued 3,213 HazCom citations. ^[4] They cluster around three failure points: missing or inaccessible SDSs, bad labels on secondary containers, and no documented training.

OSHA penalty amounts were last adjusted in January 2024 under the Federal Civil Penalties Inflation Adjustment Act. As of 2024, other-than-serious and serious violations both carry a maximum of $16,131 per violation, and willful or repeated violations run up to $161,323 per violation. ^[8] For a small business with 10 or 20 missing SDSs, those per-violation caps stack up fast.

In practice, OSHA applies a penalty reduction matrix based on employer size, good faith, and history. Employers with 10 or fewer employees can see reductions up to 60%. Employers with 11 to 25 employees, up to 40%. Those reductions only kick in if there's evidence of good faith, meaning you have a written program and training documentation, even if it's imperfect. Walk in with nothing and you get full penalties.

The priciest HazCom citations involve willful violations: an employer who knew workers were handling chemicals without SDSs and did nothing. A single willful citation for a systemic SDS failure can top $100,000.

Compare that to the cost of doing it right. Building a compliant written HazCom program, buying SDS management software, and training workers usually runs well under $2,000 for a small business. The math isn't subtle.

How do you manage Safety Data Sheets in a small workplace?

The standard requires SDSs to be accessible to workers during their shift, in their work area. ^[5] So if someone works nights with hazardous chemicals, the SDS can't sit locked in the manager's office. It has to be reachable without a supervisor's help.

You have a few ways to manage SDSs. A physical binder is the simplest, and it works fine if you have a small inventory (say, fewer than 30 chemicals) and workers who don't need SDSs in multiple locations at once. Organize it alphabetically by product name, cross-reference by CAS number, and keep a master index at the front.

Electronic SDS management works better for larger inventories or multi-location businesses. OSHA allows electronic access as long as workers are trained to use the system, there's a backup plan for outages, and the system doesn't force an employee to go through a supervisor to see a sheet. ^[7] Commercial SDS platforms range from free (manufacturer-provided portals) to a few hundred dollars per year for hosted services.

Chemical inventory management is the step most employers skip. 29 CFR 1910.1200(e)(1) requires a list of all hazardous chemicals in the workplace, each one linked to its SDS. ^[5] Walk your facility with a clipboard, open every cabinet and storage area, and write down every chemical product present. This list is also the first thing an OSHA inspector asks to see.

For chemicals tied to lockout tagout procedures or running through piping systems, you need extra documentation: what's in the pipe, the hazard class, and how workers identify it during maintenance. That belongs in your HazCom program's "methods for unlabeled pipes" section.

Does GHS apply to all workplaces and all chemicals?

No, and the exemptions matter.

OSHA's HazCom standard at 29 CFR 1910.1200 covers hazardous chemicals in general industry, construction, maritime, and agriculture. ^[5] But specific exemptions apply:

• Hazardous waste regulated by EPA under RCRA (EPA's rules govern, not OSHA HazCom).
• Tobacco products.
• Wood or wood products, where the wood itself is not treated with a hazardous chemical.
• Food, drugs, and cosmetics regulated by FDA for consumer use, when used at work in normal consumer quantities.
• Nuisance particulates and other materials specifically listed in OSHA's exemption provision.
• Articles (manufactured items that don't release hazardous chemicals in normal use).

Agriculture has its own HazCom rule, 29 CFR 1928.21, which pulls in the general industry HazCom standard by reference for most purposes.

Construction employers fall under 29 CFR 1926.59, which matches 1910.1200 in substance. ^[11] Same SDS format, same label requirements, same training obligations on the job site. The real difference is that construction sites cycle chemicals through fast and from many subcontractors, which makes SDS management harder.

Farm workers deserve a closer look. Agricultural employers with 11 or more workers, or those who use temporary labor camps, are covered by OSHA HazCom. Pesticides are the complicated case. They're exempt from HazCom's SDS requirement because EPA's pesticide label (required under FIFRA) does the same job, but employers still have to train workers on pesticide hazards. ^[5]

Not sure whether your operation is covered? The OSHA basics overview explains jurisdictional coverage and which employers sit outside federal OSHA's reach entirely (some state-plan states and industries).

How do you write or update a HazCom program to cover GHS requirements?

Most small employers should start with OSHA's free model written HazCom program, posted on OSHA's HazCom page. ^[5] It's a fill-in-the-blanks template that hits the required elements. The catch: it's generic, and an inspector who sees 50 businesses hand in the same untouched template is not impressed.

Here's what you actually need to customize:

Start with your chemical inventory. It has to reflect your real workplace, not a placeholder. Go product by product. Note the manufacturer, the CAS number or product code, where the chemical gets used, and where the SDS is filed.

Next, your labeling procedure. Spell out exactly how your facility handles secondary containers. GHS-compliant labels from a label printer? A color-coded system with a reference chart? Whatever you use, describe it in the written program and train workers on it.

Then your SDS access system. Where are SDSs stored? What's the backup if electronic access drops? Who obtains SDSs for new chemicals before they hit the floor? Name the person or the role.

Last, your training process. Who delivers training? What materials do you use? How do you prove each worker completed it? Attach a sign-in sheet template or describe your recordkeeping.

If you need this done without hiring a consultant, SafetyFolio's safety program generator runs exactly this workflow. It walks you through each required element, generates a program document keyed to your answers, and produces the documentation an OSHA inspector expects.

Review the written program any time you add a new hazardous chemical, whenever OSHA updates the HazCom standard (as it did in 2024), and at least once a year as a general audit. A stale program with no revision date is a red flag to inspectors.

Frequently asked questions

What does GHS stand for in chemical safety?

GHS stands for the Globally Harmonized System of Classification and Labelling of Chemicals. It's a United Nations framework that standardizes how chemical hazards are classified, labeled on containers, and communicated through Safety Data Sheets. OSHA folded GHS into U.S. law through its Hazard Communication Standard at 29 CFR 1910.1200, most recently updated by a final rule in May 2024.

Is a Safety Data Sheet the same as a Material Safety Data Sheet?

They serve the same purpose but use different formats. The old Material Safety Data Sheet (MSDS) had no required section order and looked different from every manufacturer. The GHS-aligned Safety Data Sheet (SDS) must follow a standardized 16-section format in a set order. After OSHA's 2012 HazCom update, MSDSs became noncompliant. All SDSs in U.S. workplaces should now follow the 16-section format.

How many pictograms are in GHS and what do they look like?

There are nine GHS pictograms: flame, flame over circle (oxidizers), exploding bomb, skull and crossbones, exclamation mark, corrosion, health hazard (torso with starburst), gas cylinder, and environment (dead tree and fish). Each is a black symbol inside a red-bordered diamond. OSHA does not currently enforce the environment pictogram under HazCom. One chemical can carry several pictograms.

What is the difference between "Danger" and "Warning" on a chemical label?

Both are GHS signal words that appear on labels, but they mark different severity levels. "Danger" applies to higher-severity hazard categories within a class, and "Warning" applies to lower-severity categories. A single label carries only one signal word. If a chemical has multiple hazard classes where one calls for "Danger" and another for "Warning," only "Danger" appears on the label.

When do employers have to comply with the HazCom 2024 changes?

Under the May 2024 final rule, chemical manufacturers and importers must update their SDSs and labels for newly added hazard classes by July 19, 2026. Distributors must ship only compliant-labeled products by January 19, 2027. Employers must update their written HazCom programs and train workers on any new hazard information by July 19, 2027.

Do temporary or seasonal workers need HazCom training?

Yes. The training requirement under 29 CFR 1910.1200 applies at the time of initial assignment to work with hazardous chemicals, regardless of employment status. Temporary workers, seasonal workers, and workers placed by staffing agencies all need training before they work with hazardous chemicals. OSHA's position is that either the host employer or the staffing agency can provide it, but someone must, and both share responsibility.

Can employers keep Safety Data Sheets on a computer or tablet instead of paper?

Yes, electronic SDS access is allowed under 29 CFR 1910.1200, but only if workers are trained to use the system, it's accessible during all shifts, and there's a reliable backup for outages or power failures. OSHA has also said the electronic system can't require a supervisor to retrieve SDSs for workers; employees must be able to reach them on their own.

What happens if a chemical supplier doesn't provide an SDS?

You are required to have an SDS for every hazardous chemical in your workplace. If a supplier fails to provide one, 29 CFR 1910.1200 requires you to contact the manufacturer or importer and request it. Document that request. If you still can't get one, you may need a different supplier. Using a chemical without an SDS, especially where workers could be exposed, creates serious liability.

Are cleaning products and common household chemicals subject to GHS HazCom rules at work?

It depends on how they're used. Consumer products used at work in the same manner and frequency as a normal consumer would use them at home are generally exempt from HazCom. But if your workers use those products in larger quantities, more often, or in ways that raise exposure beyond what a household user would face, the exemption drops away and HazCom requirements apply.

Do small businesses with fewer than 10 employees have to comply with HazCom?

Yes. The Hazard Communication Standard at 29 CFR 1910.1200 applies to all employers covered by OSHA, regardless of size, if workers may be exposed to hazardous chemicals. There is no small-employer exemption. Penalty reductions do exist: employers with 10 or fewer workers can receive up to a 60% cut in proposed penalties, but only if a good-faith effort (written program, training records) is documented.

What is an H-code and a P-code on a GHS label?

H-codes are standardized Hazard Statements assigned by GHS. For example, H225 means "Highly flammable liquid and vapour." P-codes are standardized Precautionary Statements, such as P210 ("Keep away from heat, hot surfaces, sparks, open flames and other ignition sources"). Manufacturers don't write these from scratch; the GHS system assigns specific H and P codes based on a chemical's hazard classification and category.

How do GHS rules apply to chemical mixtures versus pure substances?

For pure substances (single chemical identity), GHS classification rests on test data for that substance. For mixtures, manufacturers use a combination of whole-mixture test data (if available), bridging principles (if the mixture is similar to a tested one), and cut-off values or concentration limits for individual ingredients. If a known carcinogen is present above a set percentage, the mixture is typically classified as a carcinogen even without mixture-level data.

Does GHS cover radioactive materials?

No. Radioactive materials are explicitly excluded from the GHS framework. In the United States, radioactive materials at work are regulated by the Nuclear Regulatory Commission under a separate regime with its own labeling and communication requirements. If a workplace handles both radioactive materials and hazardous chemicals, both regulatory systems apply in parallel.

What records do employers need to keep to prove HazCom compliance?

OSHA doesn't set a retention period for HazCom training records in the standard itself, but general recordkeeping practice and inspection reality mean you should keep training records (sign-in sheets, dates, topics covered, trainer name) for at least the duration of employment plus three years. Your written HazCom program and chemical inventory should stay current and available at all times; they're the first things a compliance officer asks for during an inspection.

Sources

1. United Nations, GHS Purple Book (9th revised edition): GHS is a UN framework covering hazard classification criteria, label elements, and standardized SDS format; H-codes and P-codes are assigned by the GHS system.
2. OSHA, Hazard Communication Standard update page (HazCom 2024 final rule, May 20, 2024): The May 2024 final rule aligned HazCom with GHS Revision 7, revised and added hazard classes, expanded reproductive toxicity to cover lactation, and set staggered compliance deadlines.
3. OSHA, Hazard Communication rulemaking regulatory impact analysis (2012): OSHA projected roughly $585 million per year in reduced injuries and illnesses and about $752 million in avoided compliance costs from the standardized SDS format.
4. OSHA, Top 10 Most Cited Standards FY2023: Hazard Communication was the second most-cited OSHA standard in FY2023, with 3,213 violations issued.
5. OSHA, 29 CFR 1910.1200 Hazard Communication Standard (regulatory text): Labels must include product identifier, signal word, hazard statements, precautionary statements, pictograms, and supplier contact; SDSs must be accessible to workers on all shifts; written HazCom program and chemical inventory are required; training must occur at initial assignment.
6. OSHA, Permissible Exposure Limits (PELs) annotated table: Some SDSs cite outdated PEL values; the current OSHA PEL table should be consulted when evaluating Section 8 exposure limits.
7. OSHA, Letters of Interpretation: HazCom training and electronic SDS access: OSHA has confirmed through letters of interpretation that training must be in a language workers understand, that a brief handout alone does not satisfy training requirements, and that electronic SDS systems must allow employee self-access without supervisor filtering.
8. OSHA, Civil Penalty Amounts (2024 adjustment): As of 2024, serious and other-than-serious violations carry a maximum penalty of $16,131 per violation; willful or repeated violations carry a maximum of $161,323 per violation.
9. European Chemicals Agency (ECHA), CLP Regulation overview: The EU's CLP Regulation (EC 1272/2008) implements GHS but with deviations including a harmonized substance classification list and required environmental hazard labeling; CLP took effect in 2008.
10. OSHA, Construction HazCom standard (29 CFR 1926.59): Construction employers are covered by 29 CFR 1926.59, which incorporates the same SDS format, label requirements, and training obligations as the general industry HazCom standard.