Chemical Safety FAQ

There are exactly 9 official GHS hazard pictograms: GHS01 (Exploding Bomb), GHS02 (Flame), GHS03 (Flame Over Circle), GHS04 (Gas Cylinder), GHS05 (Corrosion), GHS06 (Skull and Crossbones), GHS07 (Exclamation Mark), GHS08 (Health Hazard), and GHS09 (Environmental). Each pictogram covers one or more hazard classes as defined by the UN Globally Harmonized System. You can see all 9 pictograms and the chemicals they apply to in our hazards database.

GHS symbols — formally called GHS hazard pictograms — are standardized graphic icons used on chemical labels and Safety Data Sheets (SDS) worldwide. They are part of the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), a framework developed by the United Nations to create a universal language for chemical hazard communication. Each symbol is a black icon inside a red diamond, and each one communicates a specific type of hazard — such as flammability, toxicity, or environmental danger. Learn more in our blog article: What Are GHS Symbols? Complete Guide to Hazard Pictograms.

Each GHS symbol communicates the type and severity of hazard a chemical presents. For example: a flame symbol (GHS02) means the substance is flammable; a skull and crossbones (GHS06) means it is acutely toxic; a health hazard symbol (GHS08) means it may be a carcinogen, mutagen, or reproductive toxin. The symbol always appears alongside a signal word (DANGER or WARNING) and one or more hazard statements (H-phrases) that specify the exact hazard. See our complete reference: GHS Hazard Symbols and Meanings.

A GHS symbol is a standardized hazard pictogram defined by the United Nations GHS document. It is a black-and-white graphic enclosed in a red diamond-shaped border, printed on chemical labels and SDS documents. GHS symbols replaced dozens of different national labelling systems with a single globally consistent approach. In the EU, GHS symbols are mandated by CLP Regulation (EC) No 1272/2008. In the USA, they are required by OSHA's Hazard Communication Standard (HazCom 2012). Search our database of 4,178 classified substances to find GHS symbols for any chemical.

GHS symbols appear in three main places: (1) Chemical labels — on containers of hazardous substances and mixtures, required by law in most countries; (2) Safety Data Sheets (SDS) — in Section 2 (Hazard Identification), which must include all applicable pictograms; (3) Hazard databases — such as the ECHA CLP Annex VI database on this site, which lists harmonized classifications for over 4,000 substances. In the EU, manufacturers must apply GHS symbols before placing any hazardous chemical on the market. Workplace safety signage and storage area markings may also use GHS-based symbols.

The GHS symbol for flammable substances is GHS02 — the Flame pictogram. It applies to flammable gases (H220, H221), flammable aerosols (H222, H223), flammable liquids (H224, H225, H226), flammable solids (H228), pyrophoric substances (H250), self-heating substances (H251, H252), and substances that emit flammable gas on contact with water (H260, H261). The most common case is flammable liquids — any liquid with a flash point below 60°C requires the GHS02 flame symbol. The signal word is DANGER for Categories 1–2 and WARNING for Categories 3–4. Browse flammable chemicals in our database.

There are two GHS symbols related to toxicity: GHS06 (Skull and Crossbones) for high acute toxicity (Categories 1–3), and GHS07 (Exclamation Mark) for lower acute toxicity (Category 4). GHS06 appears on substances where the oral LD50 is ≤ 300 mg/kg, the dermal LD50 is ≤ 1,000 mg/kg, or the inhalation LC50 is ≤ 10 mg/L/4h. The signal word is always DANGER for GHS06. Category 4 (ATE oral ≤ 2,000 mg/kg) uses GHS07 with signal word WARNING. For long-term toxic effects (carcinogens, STOT), the GHS08 Health Hazard symbol applies instead. Learn more in our article: GHS Hazard Symbols and Meanings.

The GHS symbol for corrosive substances is GHS05 — the Corrosion pictogram, which shows a liquid dripping onto a surface and a hand, both being eaten away. It applies to: substances causing skin corrosion (H314 — Causes severe skin burns and eye damage), substances causing serious eye damage (H318 — Causes serious eye damage), and substances corrosive to metals (H290 — May be corrosive to metals). The signal word for H314 and H318 is DANGER. Common corrosives include sulfuric acid, sodium hydroxide, hydrochloric acid, and hydrogen fluoride. Search for corrosive chemicals in our hazards database.

GHS symbols are only required on chemicals that meet the classification criteria for one or more hazard classes. Non-hazardous chemicals — those that do not meet any classification threshold — do not carry GHS pictograms. In the EU under CLP, manufacturers and importers must classify their substances and mixtures before placing them on the market. If a substance is on the ECHA CLP Annex VI harmonized classification list, the listed classification is mandatory. For substances not on Annex VI, manufacturers perform their own "self-classification" based on available data. Our database covers 4,178 harmonized substances from Annex VI.

The 9 official GHS pictograms are: GHS01 — Exploding Bomb (explosives, organic peroxides); GHS02 — Flame (flammable gases, liquids, solids, pyrophoric); GHS03 — Flame Over Circle (oxidisers); GHS04 — Gas Cylinder (gases under pressure); GHS05 — Corrosion (skin corrosion, eye damage, corrosive to metals); GHS06 — Skull and Crossbones (acute toxicity Cat 1–3); GHS07 — Exclamation Mark (acute toxicity Cat 4, irritants, sensitisers); GHS08 — Health Hazard (carcinogens, mutagens, reprotoxins, STOT, aspiration); GHS09 — Environmental (aquatic toxicity). Read our full guide: What Are GHS Symbols? Complete Guide to Hazard Pictograms.