The useful question is not simply how many symbols exist, but which ones a particular product actually needs. Classification determines the starting set; jurisdiction, precedence, and formatting rules shape what finally appears.
01 – The countHow many pictograms are on an SDS?
A safety data sheet displays the pictograms triggered by that product's hazard classification. A mild skin irritant might show one. A flammable, acutely toxic, corrosive solvent blend might show four. A non-hazardous product shows none at all.
Three different ideas are often collapsed into a single count:
- The GHS vocabulary contains nine pictograms.
- A specific product may need none, one, or several of them.
- OSHA's scope excludes aquatic toxicity, so the Environment pictogram is supplementary under HazCom rather than mandatory.
OSHA's Appendix C is explicit. C.2.3.2 states that one of eight standard hazard symbols shall be used in each pictogram, and Figure C.1 depicts the symbols covered by the standard. The Environment pictogram is absent from that mandatory figure. (29 CFR 1910.1200 Appendix C)
02 – The exceptionWhich pictogram is not mandatory for chemical labels and SDSs under HazCom?
The Environment pictogram, used for aquatic toxicity.
OSHA's own HCS pictogram QuickCard labels it “Non-Mandatory.” The reasoning is jurisdictional rather than scientific: OSHA regulates worker safety, and environmental hazards to aquatic life are regulated by EPA. Aquatic toxicity is not among the hazard classes in Appendix A for health hazards or Appendix B for physical hazards, so there is nothing in HazCom to trigger the symbol. (OSHA QuickCard: HCS Pictograms and Hazards)
That distinction is one example of why OSHA HazCom and the global GHS are not interchangeable: OSHA adopted the worker-hazard portions of GHS, not every class in the international system.
The environment pictogram is not illegal in the United States. Many manufacturers include it on documents used in multiple markets, where aquatic-toxicity classification may be mandatory. Under HazCom, it is supplementary information rather than a required pictogram.
The related item worth knowing: OSHA's 2024-revised QuickCard and current HazCom FAQ both flag the exclamation mark when used for “Hazardous to Ozone Layer” as non-mandatory. That status is current OSHA guidance; Appendix A does not itself contain an ozone-layer hazard class. (OSHA 3491-08R 2024; OSHA HazCom FAQ)
03 – ReferenceAll 9 GHS pictograms and what they cover
| Pictogram | OSHA status | Hazards covered |
|---|---|---|
| Health Hazard | Mandatory when triggered | Carcinogenicity, germ cell mutagenicity, reproductive toxicity, respiratory sensitization, specific target organ toxicity, aspiration hazard |
| Flame | Mandatory when triggered | Flammables, pyrophorics, self-heating, emits flammable gas, self-reactives, organic peroxides |
| Exclamation Mark | Mandatory when triggered | Skin and eye irritation, skin sensitization, acute toxicity (harmful), narcotic effects, respiratory tract irritation |
| Gas Cylinder | Mandatory when triggered | Gases under pressure and applicable chemicals under pressure |
| Corrosion | Mandatory when triggered | Skin corrosion and burns, serious eye damage, corrosive to metals |
| Exploding Bomb | Mandatory when triggered | Explosives, self-reactives, organic peroxides |
| Flame Over Circle | Mandatory when triggered | Oxidizers |
| Skull and Crossbones | Mandatory when triggered | Acute toxicity (fatal or toxic) |
| Environment | Not mandatory | Aquatic toxicity |
Several hazard classes appear twice. Self-reactives and organic peroxides trigger either the flame or the exploding bomb depending on the type. Acute toxicity triggers either the skull and crossbones or the exclamation mark depending on the category.
04 – PrecedenceThe other times a mandatory pictogram gets dropped
“Which pictogram is not mandatory?” has a second answer that shows up on real labels far more often than the environment symbol. Appendix C.2.1 sets precedence rules that actively suppress the exclamation mark:
- C.2.1.2: If the skull and crossbones pictogram is present, the exclamation mark shall not appear where it is used for acute toxicity.
- C.2.1.3: If the corrosion pictogram is present, the exclamation mark shall not appear where it is used for skin or eye irritation.
- C.2.1.4: If the health hazard pictogram is present for respiratory sensitization, the exclamation mark shall not appear where it is used for skin sensitization or for skin or eye irritation.
For the full connection between classification, pictogram precedence, and the hazard-identification block, see our guide to OSHA HazCom SDS Section 2.
A label showing both a skull and crossbones and an exclamation mark for acute toxicity is non-compliant. The lesser warning is removed when the more severe symbol communicates the same hazard.
Two more suppression or omission rules matter:
- HNOC, C.2.3.3: The exclamation mark is permitted but not required for Hazards Not Otherwise Classified, provided the words “Hazard Not Otherwise Classified” or “HNOC” appear below it.
- DOT overlap, 1910.1200(f)(5)(iii): Where a DOT pictogram required under 49 CFR appears on a shipped container, the HazCom pictogram in Appendix C.4 for that same hazard is not required on the label. This changed with the 2024 rule; the previous version prohibited showing both, while the current text makes the HazCom pictogram optional.
Worked example: four classifications become three pictograms
Assume a hypothetical solvent mixture has these four classifications:
- Flammable liquid, Category 2 initially triggers GHS02 (Flame).
- Acute toxicity, oral, Category 3 initially triggers GHS06 (Skull and Crossbones).
- Skin irritation, Category 2 initially triggers GHS07 (Exclamation Mark).
- Respiratory sensitization, Category 1 initially triggers GHS08 (Health Hazard).
The initial unique set is therefore GHS02 + GHS06 + GHS07 + GHS08. Then apply Appendix C.2.1: GHS06 removes GHS07 where it was assigned for acute toxicity, and respiratory-sensitizer GHS08 removes GHS07 where it was assigned for skin irritation. No classification is erased—the required hazard statements and precautionary statements still follow their allocations—but GHS07 has no remaining pictogram role.
GHS02 + GHS06 + GHS08. Precedence removes GHS07 from the label, reducing four initially triggered symbols to three.
05 – FormattingHow pictograms appear on an SDS versus a label
The formatting requirements are different, and this trips people up.
On a shipped container label, C.2.3.1 requires a black hazard symbol on a white background inside a red frame set at a point, wide enough to be clearly visible. A red frame with no symbol inside it is not a pictogram and is not permitted. If stock labels have preprinted empty diamonds, OSHA confirmed in a 2012 interpretation letter that fully blacking out the unused frames is compliant, but leaving them blank is not. (OSHA standard interpretation, December 20, 2012)
C.2.3.4 adds that a pictogram may appear only once on a label. If four classifications all trigger the flame, the flame still appears exactly once.
On the SDS, Section 2 is more permissive. Appendix D allows pictograms to be presented as graphical reproductions of the symbols in black and white, or as a description of the symbol name, such as “skull and crossbones” or “flame.” Color is not required, and a text list of symbol names is acceptable.
On workplace secondary containers, a black border is acceptable instead of red. Red borders are required whenever the container is shipped, regardless of where it ends up.
06 – FAQFrequently asked questions
Are there 9 or 10 GHS pictograms?
Nine. The confusion usually comes from counting DOT transport placards, which are a separate system under 49 CFR 172 and do not replace GHS pictograms.
Is the environment pictogram illegal to use in the US?
No. It is not required, but it is permitted as supplementary information and appears routinely on SDSs authored for multi-market distribution.
Do all 9 pictograms appear on every SDS?
No. Only those triggered by the product's classification appear, so the count varies with the product rather than following a standard range.
Which GHS revision is OSHA currently aligned to?
The May 2024 final rule, 89 FR 44144, aligns HazCom primarily to GHS Revision 7. It became effective July 19, 2024, with staged compliance dates. Our HazCom Revision 7 transition timeline explains which substance, mixture, distributor, and employer deadlines apply. (Hazard Communication Standard final rule)
Can I put a pictogram on a label for a hazard the product doesn't have?
No. Pictograms are assigned by classification. Adding one that the classification does not support misrepresents the hazard.
07 - DecisionsDecision rules
Start from the classification, not the pictogram list. The classification determines which symbols appear, never the reverse.
Apply the C.2.1 precedence rules before finalizing the label. The exclamation mark is the pictogram that gets suppressed.
Deduplicate. Use one instance of each pictogram per label, no matter how many classifications trigger it.
Use the environment pictogram deliberately. Include it only when an aquatic-toxicity classification and a business or destination-market reason support it. It is never required for US-only OSHA compliance.
Never leave an empty red diamond on a label. Black it out completely or use label stock that matches the actual pictogram count.
Use the SDS formatting flexibility where it helps. In Section 2, black-and-white symbols or plain symbol names are both acceptable.
08 – SymbolsGHS pictogram meanings, codes, and OSHA status
Use this reference to identify each symbol and the rules that affect whether it appears on a US shipped-container label or in Section 2 of an SDS. The classification—not the symbol alone—determines the required label elements.
GHS01
Exploding Bomb pictogram
Warns of explosive or highly reactive physical hazards. Under OSHA HazCom, it can apply to explosives and to the more hazardous types of self-reactive substances and organic peroxides.
- Applicable hazards
- Explosives, self-reactive chemicals, and organic peroxides, depending on the assigned division, type, or category.
- OSHA status
- Mandatory when allocated by Appendix C for the product's classification.
- Precedence
- No general OSHA rule suppresses GHS01; use the exact classification because not every self-reactive chemical or organic peroxide receives it.
- Confirm the assigned type or category; not every self-reactive substance or organic peroxide receives this symbol.
- Check whether Appendix C allocates both the exploding bomb and flame for the classification.
- Keep ignition, shock, friction, and temperature-control precautions aligned with the classification.
GHS02
Flame pictogram
Identifies fire-related hazards including flammables, pyrophorics, self-heating chemicals, chemicals that emit flammable gas, and certain self-reactives, organic peroxides, and desensitized explosives.
- Applicable hazards
- Flammables, pyrophorics, self-heating chemicals, chemicals that emit flammable gas, self-reactives, organic peroxides, and desensitized explosives.
- OSHA status
- Mandatory when allocated by Appendix C for the product's classification.
- Precedence
- Show the flame only once, even when several classifications trigger it; the symbol is not repeated for each hazard class.
- Classify the product in its actual physical form; gas, aerosol, liquid, and solid criteria differ.
- Use measured properties such as flash point and initial boiling point where the criteria require them.
- Show the flame only once even when several classifications trigger it.
GHS03
Flame Over Circle pictogram
Marks oxidizing gases, liquids, and solids—materials that may cause or intensify fire by contributing oxygen or otherwise supporting combustion.
- Applicable hazards
- Oxidizing gases, oxidizing liquids, and oxidizing solids.
- OSHA status
- Mandatory when allocated by Appendix C for the product's classification.
- Precedence
- No general pictogram-suppression rule removes GHS03; deduplicate it if more than one oxidizer classification triggers the symbol.
- Do not treat an oxidizer as though it were simply a flammable material; the hazard mechanism is different.
- Separate oxidizers from fuels, reducing agents, and incompatible organic materials.
- Verify the oxidizer category before allocating the signal word and hazard statements.
GHS04
Gas Cylinder pictogram
Communicates hazards from gases under pressure and, under HazCom 2024, applicable chemicals under pressure. The container may rupture if heated, and refrigerated gases can cause cryogenic injury.
- Applicable hazards
- Gases under pressure and applicable chemicals under pressure under the 2024 Hazard Communication Standard.
- OSHA status
- Mandatory when allocated by Appendix C for the product's classification.
- Precedence
- Aerosols are not classified as gases under pressure under HazCom 2024; classify aerosols and chemicals under pressure in their own hazard classes before assigning GHS04.
- Distinguish gases under pressure, aerosols, and chemicals under pressure before assigning the symbol.
- Protect containers from heat and physical damage and follow the applicable storage statement.
- Revisit older aerosol classifications when converting documents to HazCom 2024.
GHS05
Corrosion pictogram
Applies to skin corrosion, serious eye damage, and corrosivity to metals. The same symbol can therefore represent a health hazard, a physical hazard, or both.
- Applicable hazards
- Skin corrosion, serious eye damage, and corrosivity to metals.
- OSHA status
- Mandatory when allocated by Appendix C for the product's classification.
- Precedence
- When GHS05 appears, do not also show GHS07 where the exclamation mark would communicate only skin or eye irritation.
- Keep the human-health and metals-corrosion classifications separate in the classification record.
- When corrosion is present, suppress the exclamation mark used only for skin or eye irritation.
- Match glove, eye-protection, first-aid, and spill language to the actual corrosive hazard.
GHS06
Skull and Crossbones pictogram
Signals severe acute toxicity. Under OSHA HazCom, acute toxicity Categories 1, 2, and 3 can trigger the skull and crossbones for the relevant exposure route.
- Applicable hazards
- Acute toxicity that is fatal or toxic by the oral, dermal, or inhalation route.
- OSHA status
- Mandatory when allocated by Appendix C for the product's classification.
- Precedence
- If GHS06 is present for acute toxicity, GHS07 must not also appear for acute toxicity.
- Classify oral, dermal, and inhalation routes independently; one route may drive the symbol.
- Document the acute toxicity estimate and any mixture conversion values used.
- Suppress the exclamation mark when it would communicate acute toxicity for the same product.
GHS07
Exclamation Mark pictogram
Covers less severe acute toxicity, skin and eye irritation, skin sensitization, respiratory tract irritation, and narcotic effects. OSHA also permits limited non-mandatory uses.
- Applicable hazards
- Harmful acute toxicity, skin or eye irritation, skin sensitization, respiratory tract irritation, and narcotic effects.
- OSHA status
- Mandatory when triggered, except for limited optional uses such as an HNOC identified as such.
- Precedence
- GHS07 is suppressed for specified hazards when GHS06, GHS05, or GHS08 already communicates the more severe hazard.
- Apply the Appendix C precedence rules before finalizing the label; this is the symbol most often suppressed.
- For an HNOC, its use is optional and must be identified with “HNOC” or “Hazard Not Otherwise Classified.”
- OSHA guidance lists hazardous to the ozone layer as a non-mandatory use.
GHS08
Health Hazard pictogram
Represents serious or chronic health effects: carcinogenicity, germ cell mutagenicity, reproductive toxicity, respiratory sensitization, target organ toxicity, and aspiration hazard.
- Applicable hazards
- Carcinogenicity, germ cell mutagenicity, reproductive toxicity, respiratory sensitization, target organ toxicity, and aspiration hazard.
- OSHA status
- Mandatory when allocated by Appendix C for the product's classification.
- Precedence
- When GHS08 appears for respiratory sensitization, GHS07 is suppressed where it would communicate skin sensitization or skin or eye irritation.
- Base chronic-hazard classifications on the applicable weight of evidence, not the symbol alone.
- When used for respiratory sensitization, apply the rule that can suppress the exclamation mark.
- Keep route-specific and target-organ details clear in the hazard statements and SDS.
GHS09
Environment pictogram
Identifies hazards to the aquatic environment. It is part of the GHS system but is not mandatory under OSHA HazCom because environmental hazards are outside OSHA's jurisdiction.
- Applicable hazards
- Hazards to the aquatic environment.
- OSHA status
- Not mandatory under OSHA HazCom; it may appear as supplementary information when an aquatic classification supports it.
- Precedence
- GHS09 is outside OSHA's eight mandatory symbols and must not contradict or cast doubt on required HazCom label information.
- Include it only when an aquatic-toxicity classification supports it.
- Check destination-market requirements before deciding whether a multi-market label or SDS should display it.
- Treat it as supplementary information on a US HazCom document and do not let it contradict required elements.
09 - AuthorityPrimary sources
- 29 CFR 1910.1200 Appendix C — Allocation of Label Elements (Mandatory)
- 29 CFR 1910.1200 — Hazard Communication
- OSHA QuickCard: HCS Pictograms and Hazards
- OSHA standard interpretation, December 20, 2012 — Pictogram requirements for product labels
- Hazard Communication Standard final rule, 89 FR 44144 (May 20, 2024)
This article is general regulatory analysis for SDS and label authoring workflows. It is not legal advice. Confirm product-specific obligations against the current text of 29 CFR 1910.1200 and any applicable state, transport, customer, or destination-market requirements. Primary sources were last checked on August 2, 2026.