The Biohazard Symbol
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U+2623
About the Biohazard Symbol
Origin & History
The biohazard symbol was developed by the Dow Chemical Company in 1966 for their containment products. Charles Baldwin, an environmental health engineer working for Dow at the time, contributed to its development. In 1967, the Centers for Disease Control (CDC) registered the symbol with the U.S. Patent and Trademark Office.
Design Purpose
The symbol was designed to be highly recognizable and memorable, even to those who have never seen it before. It does not resemble any existing religious or cultural symbols to avoid confusion. The distinctive trefoil design consists of three interconnected circles, symbolizing a biological threat.
Usage & Meaning
The biohazard symbol identifies biological substances that pose a health risk, including:
- Biological waste and contaminated materials
- Medical waste
- Laboratories handling infectious agents
- Areas with biological hazards
- Equipment contaminated with biohazardous materials
Color Standards
The official biohazard symbol is traditionally black on a yellow/orange background. This high-contrast combination ensures visibility and recognition even in poor lighting conditions.
Standardized Hazard Symbol Systems
List of Standardized Hazard Symbol Systems
| Standard | Warning Type | Scope | Audience | Status |
|---|---|---|---|---|
| ISO 7010 warning symbols | Warning | General purpose warning symbols | The general public | Currently used |
| GHS hazard pictograms | Warning | The labelling of containers and for workplace hazard warnings, and for use during the transport of dangerous goods | The general public, the workplace, and material transport personnel | Currently used |
| NFPA 704 Safety Square | Warning | To quickly and easily identify the risks posed by hazardous materials | Emergency response personnel | Currently used in the US |
| Hazardous Materials Identification System | Warning | A numerical hazard rating used to identify the risks posed by hazardous materials | Employers and workers who handle and are exposed to hazardous chemicals | Currently used in the US |
| EU Directive 67/548/EEC | Warning | The labelling of containers in the EU, used until 2017 | Mixtures of chemicals that are placed on the market in the European Union | No longer used |
| WHMIS 1988 | Warning | Workplace hazard warnings used in Canada, mostly replaced by GHS as of 2018 | Workplace Hazards in Canada | No longer used, except biological hazard symbol |
Examples of Common Hazard Symbols
| Warning Type | ISO 7010 | ANSI Z535 (United States) |
|---|---|---|
| General warning sign | ISO 7010 W001 | -- |
| Flammable material | ISO 7010 W021 | USA flammable |
| Explosive materials | ISO 7010 W002 | USA explosion hazard |
| Toxic material | ISO 7010 W016 | Poison |
| Corrosive substance | ISO 7010 W023 | USA corrosive material |
| Electricity hazard | ISO 7010 W012 | USA electric shock |
| Radioactive material or ionizing radiation | ISO 7010 W003 | USA radiation hazard |
| Biological hazard | ISO 7010 W009 | US ANSI Biohazard Symbol |
| Floor-level obstacle | ISO 7010 W007 | |
| Drop or fall hazard | ISO 7010 W008 | |
| Slippery surface | ISO 7010 W011 |
Common Applications
Medical & Laboratory
Medical facilities, research laboratories, and healthcare settings use the biohazard symbol to mark containers, bags, rooms, and equipment that contain or are contaminated with biological substances that could pose a threat to health.
Waste Management
Biohazardous waste containers, such as sharps containers and medical waste bags, are labeled with the symbol to ensure proper handling and disposal of potentially infectious materials.
Transportation
Vehicles and containers transporting biohazardous materials display the symbol to alert handlers and emergency responders to the potential dangers of the contents.
Digital & Creative
The biohazard symbol has also been adopted in digital media, games, and creative works to symbolize danger, contamination, or biological threats in fictional contexts.