Based on the hazard classes, hazmat placards are of the following types: 1. Hazard Class 1 Placard — Explosives These are for explosives such as TNT, ammunition, fireworks, and airbag inflators. Orange in color, these placards have one of six sub-categories: 1: Mass Explosion Hazard 2: Mass Projection Hazard 3: Fire/Minor Blast/Minor Projection Hazard 4: Minor Explosion Hazard 5: Blasting Agent 6: Very Insensitive Materials 2. Hazard Class 2 Placard — Gases These are for fire extinguishers, aerosols, propane tanks, and gas cartridges. Placards colors signify the following: - Green: Non-Flammable Gas - Red: Flammable Gas - White: Toxic Gas - Yellow: Oxygen Gas - White with Black Skull Inset: Inhalation Hazard 3. Hazard Class 3 Placard — Flammable and combustible liquids These are for flammable liquids like gasoline, paint, acetone, and kerosene. Red in color, these placards identify liquid substances having a flashpoint less than 60 °Celcius (140 °F), or any material in a liquid phase with a flashpoint at or above 37.8 °Celcius (100 °F). 4. Hazard Class 4 Placard — Flammable materials These are for flammable solids such as matches, powdered metals, and activated carbon. Different color schemes mean the following: - Red and White Stripes: Flammable Solids - Upper Half White, Lower Half Red: Spontaneously Combustible Solids - Blue: Water-Reactive Solids 5. Hazard Class 5 Placard — Oxidizer and organic peroxide These are for oxidizing substances and organic peroxides such as ammonium nitrate fertilizer and chemical oxygen generators. They have two different categories: - Yellow: Oxidizer - Red Top, Yellow Bottom: Organic Peroxide 6. Hazard Class 6 Placard — Poisons These are for toxic and/or infectious substances like regulated medical waste, tear gas, and strong poisons such as cyanides and neonicotinoids. They have two design schemes: - White: Toxic - White with Black Skull Inset: Inhalation Hazard 7. Hazard Class 7 Placard — Radioactive These are for radioactive substances such as medical isotopes and radioactive ore. They have a yellow top that features the international symbol for radiation and a white bottom. 8. Hazard Class 8 Placard — Corrosive These are for corrosive chemicals such as strong acids, lye, and certain dyes and paints. They have a white top with an illustration of a chemical burning a human hand and a black bottom. 9. Hazard Class 9 Placard — Miscellaneous These are for other hazardous substances such as dry ice and lithium-ion batteries. These placards have a black and white striped top half and a white bottom.