Safety data sheet pictograms: all 9 GHS symbols explained

Last updated 2026-07-09

What are GHS pictograms and why do they appear on safety data sheets?

GHS stands for the Globally Harmonized System of Classification and Labelling of Chemicals. It's a United Nations framework that standardizes how hazardous chemicals are identified worldwide. OSHA adopted GHS into its Hazard Communication Standard in 2012, with full employer compliance required by June 1, 2016. ^[1]

Pictograms are the visual shorthand of that system. Each one is a black symbol inside a red diamond, and each diamond maps to one or more hazard categories. The point of standardizing them globally is that a worker in Texas and a worker in South Korea see the same symbol and understand the same hazard.

On a safety data sheet (SDS), pictograms appear in Section 2 (Hazard Identification), alongside signal words, hazard statements, and precautionary statements. The SDS format itself has 16 mandatory sections under 29 CFR 1910.1200, Appendix D. ^[2] Pictograms are also required on the physical container label, so there's a deliberate redundancy: what's on the drum should match what's in the SDS.

If you're looking up safety data sheets online for chemicals your business uses, you'll see these same nine pictograms across every SDS from every manufacturer, because the format is legally standardized. That consistency is the whole point.

What are the 9 GHS hazard pictograms and what does each one mean?

OSHA recognizes nine GHS pictograms under 29 CFR 1910.1200. ^[1] Here's what each one signals and the hazard classes it covers.

Pictogram Name	Symbol Description	Hazard Classes Covered
Flame	Flame over a surface	Flammable gases, aerosols, liquids, solids; self-reactive substances; pyrophoric materials; self-heating substances; substances that emit flammable gas in contact with water
Flame Over Circle	Flame over a circle	Oxidizers (gases, liquids, solids)
Exploding Bomb	Exploding shell	Explosives; self-reactive substances (Type A/B); organic peroxides (Type A/B)
Compressed Gas	Gas cylinder	Gases under pressure: compressed, liquefied, dissolved, refrigerated liquefied
Corrosion	Liquids dripping onto a hand and a surface	Skin corrosion/burns; serious eye damage; corrosive to metals
Skull and Crossbones	Skull over two crossed bones	Acute toxicity (fatal or toxic): oral, dermal, or inhalation routes
Exclamation Mark	Bold exclamation point	Acute toxicity (harmful); skin/eye irritation; skin sensitization; specific target organ toxicity (single exposure); respiratory tract irritation; narcotic effects; hazardous to ozone layer
Health Hazard	Silhouette of a person with a starburst on the chest	Carcinogens; respiratory sensitizers; reproductive toxins; specific target organ toxicity (repeated exposure); aspiration hazard; germ cell mutagens
Environment	Dead tree with dead fish	Aquatic toxicity (acute and chronic)

A few things about this table worth knowing. The skull and crossbones is reserved for the most severe acute toxicity categories (1 through 3 on the GHS scale). The exclamation mark covers the less severe category (4). You will not see both on the same SDS for the same route of exposure, because the more severe symbol takes precedence. ^[3]

The environment pictogram is the only one OSHA does not formally require on labels under the current HazCom standard, though it's still on many SDS documents because chemical manufacturers follow the UN GHS guidance directly. ^[1]

The health hazard silhouette (sometimes called the "exploding chest" in training) covers carcinogens. That's the one that tends to get the most attention in workplaces handling solvents, certain dusts, or pesticides.

Where exactly do pictograms appear on a safety data sheet?

Section 2 of every SDS is titled "Hazard(s) Identification" and it must include, at minimum: the GHS product identifier, hazard classification, signal word, hazard statements, pictograms, and precautionary statements. ^[2] That's required under 29 CFR 1910.1200, Appendix D.

In practice, most SDSs show the pictograms as small printed images near the top of Section 2. Some show them as text descriptors ("Flame," "Skull and Crossbones") if the document is formatted for screen-reader accessibility, though the physical label on the container must show the actual graphic symbols.

Section 2 also includes the signal word. There are only two: "Danger" for the more severe hazard categories, and "Warning" for less severe. ^[3] A chemical can have multiple pictograms but only one signal word, and if the hazard categories warrant both, "Danger" wins.

One thing that trips people up: a chemical can legitimately have zero pictograms if it doesn't meet GHS classification thresholds. The SDS still exists for it, but Section 2 will note that no hazard classification applies. That's uncommon for industrial chemicals but happens with some diluted mixtures.

What does the flame pictogram mean on a safety data sheet?

The flame is the most common pictogram you'll see in most workshops, warehouses, and manufacturing environments. It covers every flammability-related hazard, from liquids and gases to solids that ignite on their own. ^[1]

For liquids, the key threshold is flash point. A flammable liquid has a flash point below 60°C (140°F), with sub-categories based on how low that flash point is. Category 1 flammable liquids (flash point below 23°C and initial boiling point at or below 35°C) are the most hazardous. Gasoline, acetone, and many cleaning solvents fall into Category 1 or 2.

The flame pictogram also appears on pyrophoric materials, which ignite spontaneously in air, and on self-heating substances. These are rarer in typical small business environments but common in certain manufacturing and chemical processing operations.

When you see the flame pictogram, the precautionary statements in Section 2 will tell you specifics: keep away from heat and ignition sources, no smoking nearby, store in a well-ventilated place, use non-sparking tools. Those aren't suggestions. They're control measures tied to the hazard classification.

What does the skull and crossbones pictogram mean, and how is it different from the exclamation mark?

The skull and crossbones means the chemical can kill or cause severe harm through a single exposure at relatively low doses. GHS acute toxicity categories 1, 2, and 3 get this symbol. ^[3]

Category 1 is the most severe. For oral exposure, that means an LD50 (the dose that kills 50% of a test population) of 5 mg/kg body weight or less. Hydrogen cyanide and certain organophosphate pesticides fall here.

The exclamation mark covers Category 4 acute toxicity, which is still harmful but less immediately deadly. It also covers irritants, mild sensitizers, and some one-time organ effects. If you see the exclamation mark without the skull and crossbones, the chemical warrants caution but is less likely to be acutely fatal.

One common question: can both appear on the same SDS? For the same exposure route, no. OSHA's GHS rules say the more severe classification takes precedence, so skull and crossbones replaces the exclamation mark for that route. But a chemical could have skull and crossbones for inhalation and exclamation mark for skin irritation, because those are different hazard classes. ^[3]

For anyone handling chemicals that carry the skull and crossbones, check Section 8 of the SDS for required PPE and Section 4 for first aid measures. Those sections carry the actionable response information.

What does the health hazard pictogram mean on an SDS?

The health hazard pictogram (the silhouette with a starburst on the chest) covers long-term or serious health effects that often don't show up immediately. Carcinogens, reproductive toxins, respiratory sensitizers, germ cell mutagens, and substances that cause repeated-exposure organ damage all get this symbol. ^[1]

This is the pictogram that matters most for chronic exposure. A worker who uses a solvent with the health hazard pictogram every day for ten years faces a different risk profile than someone who uses it once.

OSHA's cancer burden data shows why this matters in practice. The agency estimates that occupational exposure to carcinogens is associated with tens of thousands of cancer deaths annually in the U.S., though precise attribution is difficult because occupational and lifestyle exposures overlap. ^[4]

If a chemical in your facility carries this pictogram, that's a trigger to look hard at your hazard communication program, your exposure controls, and whether your written program addresses that specific chemical. It's also a trigger to check Section 8 of the SDS for permissible exposure limits (PELs), which OSHA sets at 29 CFR 1910.1000 for common substances.

What does the corrosion pictogram mean, and what PPE does it require?

The corrosion pictogram shows liquid dripping onto a hand and a flat surface, signaling that the substance destroys tissue or materials on contact. It covers three hazard types: skin corrosion, serious eye damage, and metals corrosion. ^[1]

HCl (hydrochloric acid) is a textbook example. If you want to see what corrosion hazard documentation looks like in practice, the hcl safety data sheet covers that specific chemical in detail. Strong bases like sodium hydroxide also carry this pictogram.

Skin corrosion under GHS means irreversible damage to skin tissue, more than redness that clears up. Serious eye damage means irreversible effects to the eye or severe corneal clouding. These are worse outcomes than skin or eye irritation, which get the exclamation mark instead.

The PPE response to corrosion hazards typically includes chemical-resistant gloves (the specific glove material matters, more than any rubber glove), splash goggles or a face shield, and possibly a lab coat or apron. Section 8 of the SDS will specify the minimum protection. Don't guess. The right glove material for hydrofluoric acid is completely different from what works for acetic acid, even though both carry the corrosion pictogram.

For corrosive materials that damage metals, this matters for storage and containment, more than personal protection. Check Section 7 (Handling and Storage) of the SDS for material compatibility requirements.

How does OSHA require employers to train workers on SDS pictograms?

29 CFR 1910.1200(h) is the training section of the Hazard Communication Standard. It requires employers to provide training at the time of initial assignment and when new chemical hazards are introduced. Training must cover how to read an SDS, how to interpret labels including pictograms, and what the information means for the worker's specific tasks. ^[5]

The standard doesn't specify a minimum number of training hours. It specifies outcomes: workers must understand what the symbols mean and what to do in response. A 20-minute focused session on pictograms with hands-on SDS review can satisfy the requirement better than a 2-hour lecture that nobody retains.

OSHA's guidance on what training must cover includes the physical and health hazards of the chemicals in the work area, protective measures employees can take, and how to detect the presence or release of hazardous chemicals. ^[5] Pictograms are one piece of that, not the whole training.

For small businesses building out a full HazCom program from scratch, this is where a tool like SafetyFolio's safety program generator can help you document the training component quickly without starting from a blank page. But the substance of the training, which is your actual chemical inventory and what each pictogram means for your specific workplace, is something you have to populate with real information about your site.

For OSHA training that goes beyond HazCom, the OSHA 30 course covers hazard communication in the context of a broader safety curriculum.

What are the OSHA citation risks if pictograms are wrong or missing?

OSHA enforces the Hazard Communication Standard under 29 CFR 1910.1200, and HazCom consistently ranks among the top 10 most cited standards every year. In fiscal year 2023, Hazard Communication was the second most cited OSHA standard, with 3,213 violations recorded. ^[6]

Missing or incorrect pictograms on labels is a citable violation. So is having an SDS that doesn't match the current GHS format (the old MSDS format is no longer compliant). So is failing to have an SDS for every hazardous chemical in the workplace.

OSHA's penalty structure as of 2024 sets serious violations at up to $16,131 per violation, with willful or repeated violations up to $161,323. ^[7] A single inspection that finds multiple chemicals with missing or incorrect labels can stack into a significant penalty.

The practical risk most small businesses face isn't usually a blatant missing SDS. It's more subtle: an SDS that was downloaded five years ago and hasn't been updated when the manufacturer revised its formulation, or a label that was reprinted without the correct pictograms after a container was refilled. These are process failures, and they show up during inspections.

For manufacturers or importers who actually create SDSs rather than just receive them, the standards are stricter. They must classify the chemical themselves and ensure every pictogram is accurate for that classification. For downstream employers, the obligation is to obtain and maintain current SDSs and make sure workers can access them.

How do you read an SDS section by section if you find a pictogram you don't recognize?

Start with Section 2. Every SDS has it, and it lists the pictograms by name or image along with the signal word, specific hazard statements (like "H225: Highly flammable liquid and vapour"), and precautionary statements. The hazard statements use an "H" number code, and precautionary statements use a "P" number code. These are standardized globally under the GHS. ^[3]

Once you've identified the hazard from Section 2, move to the sections that tell you what to do about it:

• Section 4: First Aid Measures. What to do immediately if someone is exposed.
• Section 5: Fire Fighting Measures. Relevant if the flame, flame over circle, or exploding bomb pictogram appears.
• Section 6: Accidental Release Measures. Spill response.
• Section 7: Handling and Storage. Practical controls.
• Section 8: Exposure Controls and PPE. Required protection, including PELs and TLVs.

Sections 11 and 12 go deeper on toxicological and ecological information if you need the underlying data. For a carcinogen (health hazard pictogram), Section 11 will describe the cancer classification (IARC Group, NTP listing, or OSHA-regulated carcinogen status).

If you're searching for safety data sheets online for chemicals you don't have on hand, the manufacturer's website is always the authoritative source. OSHA also maintains guidance on SDS requirements at OSHA.gov. Some industries use third-party SDS databases, but always verify the version date matches what the manufacturer currently distributes.

Are the same pictograms used in Canada, Europe, and other countries?

Yes, with minor differences. The GHS system is a UN framework, so the core pictograms are the same globally. A flame symbol means flammability in Canada, the EU, Japan, and the U.S. ^[3]

The differences are in how each country implemented GHS and which edition they adopted. OSHA's current HazCom standard is aligned with the third revised edition of the UN GHS (Rev.3), though OSHA published a notice of proposed rulemaking in 2021 to update to Rev.7 for some provisions. ^[8] The EU is on a different version. Canada adopted GHS through WHMIS 2015.

For most practical purposes, the nine pictograms are visually identical across jurisdictions. Where you'll notice differences is in the exact hazard classification thresholds, the signal word conventions, and some supplemental label elements. An SDS formatted for Canada under WHMIS will look very similar to a U.S. SDS but may have slight differences in Section 15 (Regulatory Information).

For companies importing chemicals, the SDS you receive from a foreign supplier should still use the same GHS pictograms. If the supplier provides an SDS formatted for their home country's GHS implementation, it may need review to confirm it meets 29 CFR 1910.1200's requirements before you use it as-is in your HazCom program.

What's the best way to build a pictogram training program for your team?

Keep it concrete and specific to your actual chemical inventory. Generic training that shows all nine pictograms and moves on doesn't stick. Training that shows the flame pictogram on the exact acetone SDS sitting on your shelf, then walks through what that means for how you store and handle it, does stick.

Here's a practical approach that works:

1. Pull your chemical inventory. Every employer should maintain a list of all hazardous chemicals on site under 29 CFR 1910.1200(e). ^[5] If you don't have one, start there. 2. For each chemical, identify which pictograms appear on its SDS. Group chemicals by shared pictograms (all your flammables together, all your corrosives together). 3. Run a 20-30 minute session per hazard group. Show the pictogram, explain what it means in plain language, walk through the relevant SDS sections, demonstrate the required PPE, and show where the SDS is kept. 4. Document the training. Date, topics covered, employee names and signatures. OSHA doesn't specify a form, but you need to show it happened. 5. Repeat when you add a new chemical or when an existing SDS gets a significant revision.

For small businesses that need to get a written HazCom program documented fast, SafetyFolio's safety program generator builds the written program structure in about 15 minutes, which you can then populate with your specific chemicals and training records. The written program is required under 29 CFR 1910.1200(e)(1). ^[5]

For lockout tagout procedures and other safety programs your team may also need, the same documentation discipline applies: written, trained, and recordable.

What are common mistakes employers make with SDS pictograms?

The most common mistake is treating the SDS as a one-time compliance checkbox rather than a living document. Manufacturers update SDSs when formulations change or when new hazard data emerges. An SDS from 2017 for a product that was reformulated in 2022 may have entirely different pictograms, and using the old version leaves you with inaccurate hazard information and a compliance gap.

The second common mistake is accessibility. 29 CFR 1910.1200(g)(8) says SDSs must be readily accessible to employees during their work shift in their work area. ^[5] That means not locked in an office, not in a binder that requires a manager's key, and not only on a computer that workers don't have access to. If you use an electronic SDS system, you need a backup plan for when systems go down.

Third: assuming that a pictogram-free label means a chemical is safe. Some chemicals are hazardous under OSHA but don't meet GHS classification thresholds at their working concentration. That doesn't mean they're benign. And some employers mislabel diluted mixtures without rechecking whether the dilution actually changes the classification.

Fourth: not training temporary or seasonal workers. 29 CFR 1910.1200(h) applies before initial assignment to a work area with hazardous chemicals. ^[5] That includes temps and contract workers if you control the work area. This is a common audit finding.

Frequently asked questions

How many GHS pictograms are there?

There are nine GHS hazard pictograms recognized under OSHA's Hazard Communication Standard (29 CFR 1910.1200): flame, flame over circle, exploding bomb, compressed gas, corrosion, skull and crossbones, exclamation mark, health hazard, and environment. Each one is a black symbol inside a red diamond border. A single SDS can carry multiple pictograms if the chemical has multiple hazard classifications.

What does the exclamation mark pictogram mean on a safety data sheet?

The exclamation mark covers less severe but still significant hazards: acute toxicity Category 4 (harmful, not fatal), skin and eye irritation, skin sensitization, mild respiratory irritation, narcotic effects, and some single-exposure organ effects. It's essentially the "caution" tier. If a chemical carries both the exclamation mark and the skull and crossbones for the same route of exposure, the skull and crossbones takes precedence and the exclamation mark is dropped for that hazard.

Do all chemicals need an SDS with pictograms?

No. Only chemicals that meet GHS hazard classification criteria require an SDS with pictograms in Section 2. Some diluted mixtures and certain articles (solid objects that don't release hazardous chemicals under normal use) may not require an SDS at all under 29 CFR 1910.1200. However, if there's any doubt, manufacturers typically provide an SDS anyway. The absence of pictograms doesn't automatically mean a chemical is safe.

What is the difference between a safety data sheet and an MSDS?

MSDS (Material Safety Data Sheet) was the old format used before OSHA adopted GHS in 2012. The SDS replaced it with a standardized 16-section format required under 29 CFR 1910.1200, Appendix D. The MSDS had no uniform structure, so sections varied by manufacturer. Full compliance with the SDS format was required by June 1, 2016. MSDSs are no longer compliant and should be replaced.

Where can I find safety data sheets online for free?

The best source is always the chemical manufacturer's website, where the most current version lives. Many manufacturers also provide SDS lookup tools. Some third-party databases aggregate SDSs, but version accuracy can lag. OSHA.gov has guidance on SDS requirements and links to resources. For regulatory verification, the manufacturer's SDS is authoritative, and 29 CFR 1910.1200 requires the SDS reflect current hazard classification.

Which GHS pictogram indicates a carcinogen?

The health hazard pictogram, which shows a silhouette of a human figure with a starburst on the chest, indicates carcinogens along with respiratory sensitizers, reproductive toxins, germ cell mutagens, specific target organ toxicants (repeated exposure), and aspiration hazards. If you see this symbol on an SDS, check Section 11 (Toxicological Information) for details on cancer classification, including whether the substance appears on IARC, NTP, or OSHA carcinogen lists.

What does the compressed gas pictogram mean in practice?

The compressed gas pictogram (a gas cylinder) appears on SDSs for gases stored under pressure: compressed gas, liquefied gas, refrigerated liquefied gas, and dissolved gas. The hazard is physical, not necessarily toxic. These cylinders can explode if heated or damaged, and they can rapidly displace oxygen in confined spaces. Propane, oxygen, acetylene, and CO2 cartridges all carry this symbol. Storage requirements are in Section 7 of the SDS.

How often should employers update their SDS files?

OSHA requires the most current SDS available from the manufacturer, but doesn't specify a fixed update schedule. The practical standard is to obtain an updated SDS whenever you receive a new shipment of a chemical and to periodically check manufacturer websites for revisions. A common industry practice is an annual review of the chemical inventory and SDS library. If a manufacturer issues a revised SDS with new or changed pictograms, training should be updated accordingly.

What is the signal word on a safety data sheet and how does it relate to pictograms?

Signal words are "Danger" or "Warning" and appear in Section 2 alongside pictograms. "Danger" applies to the more severe hazard categories within each class; "Warning" applies to less severe categories. A single chemical has only one signal word even if it has multiple pictograms covering different hazard classes. If any applicable hazard category warrants "Danger," that signal word is used on the label and SDS regardless of other hazards.

Can a small business be cited by OSHA for pictogram violations?

Yes. OSHA's Hazard Communication Standard applies to all employers with workers who may be exposed to hazardous chemicals, regardless of company size. Hazard Communication was the second most cited OSHA standard in fiscal year 2023 with over 3,200 violations. Common citation triggers include missing or outdated SDSs, labels without required pictograms, no written HazCom program, and failure to train employees before assignment to work areas with hazardous chemicals.

Does the environment pictogram mean the chemical is regulated as a hazardous waste?

Not automatically. The environment pictogram on an SDS signals aquatic toxicity under GHS classification, but hazardous waste status under RCRA (the Resource Conservation and Recovery Act) is a separate determination governed by EPA, not OSHA. A chemical with the environment pictogram may or may not qualify as RCRA hazardous waste depending on its specific listing or characteristic. Check with EPA regulations or an environmental consultant for waste disposal questions.

Do I need pictogram training for office workers who don't handle chemicals directly?

It depends on whether they're exposed to hazardous chemicals in their work area. 29 CFR 1910.1200(h) requires training for employees who may be exposed to hazardous chemicals under normal conditions or in a foreseeable emergency. A pure office worker with no chemical exposure may not require full HazCom training, but if the office shares space with a production area or uses cleaning chemicals, some level of training is appropriate. When in doubt, train them.

What's the difference between a hazard statement and a precautionary statement on an SDS?

Hazard statements describe the nature and degree of the hazard, using standardized "H" codes (for example, H225 means "Highly flammable liquid and vapour"). Precautionary statements tell you what to do about it, using "P" codes (for example, P210 means "Keep away from heat, sparks, open flames"). Both are required in Section 2 of every SDS under 29 CFR 1910.1200, Appendix D. They're standardized globally under the UN GHS framework so the language is consistent across manufacturers.

Sources

1. OSHA, Hazard Communication Standard (29 CFR 1910.1200): OSHA adopted GHS into its Hazard Communication Standard in 2012; nine pictograms are required; environment pictogram not formally required on U.S. labels
2. OSHA, 29 CFR 1910.1200 Appendix D, Safety Data Sheet Requirements: SDS must have 16 sections; pictograms appear in Section 2 (Hazard Identification)
3. United Nations, Globally Harmonized System of Classification and Labelling of Chemicals (GHS) Purple Book: GHS defines signal words (Danger/Warning), H-codes, P-codes, skull and crossbones vs. exclamation mark precedence rules, and standardized pictogram meanings
4. OSHA, 29 CFR 1910.1200 Full Standard Text: Training required at initial assignment and when new hazards introduced (1910.1200(h)); written program required (1910.1200(e)(1)); SDS accessibility required (1910.1200(g)(8)); chemical inventory required (1910.1200(e))
5. OSHA, Top 10 Most Frequently Cited Standards FY2023: Hazard Communication was the second most cited OSHA standard in FY2023 with 3,213 violations
6. OSHA, Penalties: As of 2024, serious violations carry penalties up to $16,131; willful or repeated violations up to $161,323 per violation
7. OSHA, Hazard Communication Update Rulemaking (HazCom 2021 NPRM): OSHA published a notice of proposed rulemaking in 2021 to update HazCom alignment toward GHS Rev.7 provisions
8. OSHA, GHS Pictogram Guidance: OSHA publishes official descriptions and images of all nine GHS pictograms and their associated hazard classes