HTML Entity for Biohazard Sign (☣)

Beginner
⏱️ 5 min read
📚 Updated: May 2026
🎯 1 Code Example
Unicode U+2623
HTML entity for Biohazard sign (U+2623) tutorial illustration

What You'll Learn

How to display the Biohazard sign (☣) in HTML and CSS. This character is U+2623 (BIOHAZARD SIGN) in the Miscellaneous Symbols block. It warns of biological hazards (infectious material, regulated medical waste, BSL areas). The design dates to the 1960s and is widely used on signage and labels worldwide.

There is no named HTML entity for U+2623. Use ☣ or ☣ in markup, or \2623 in stylesheet content. For real-world labeling, follow national regulations (for example OSHA/GHS in the United States); a Unicode glyph in HTML is not a substitute for compliant label artwork.

⚡ Quick Reference — Biohazard Sign

Unicode U+2623

Miscellaneous Symbols

Hex Code ☣

Hexadecimal reference

HTML Code ☣

Decimal reference

Named Entity —

None (use numeric refs)

Reference Table
Name           Value
────────────   ──────────
Unicode        U+2623
Hex code       ☣
HTML code      ☣
Named entity   —
CSS code       \2623
1

Complete HTML Example

This example shows the Biohazard sign using hexadecimal and decimal character references, plus a CSS content escape on a pseudo-element:

html
<!DOCTYPE html>
<html>
<head>
 <style>
  #point:after{
   content: "\2623";
  }
 </style>
</head>
<body>
<p>Biohazard Sign using Hexa Decimal: &#x2623;</p>
<p>Biohazard Sign using HTML Code: &#9763;</p>
<p id="point">Biohazard Sign using CSS Entity: </p>
</body>
</html>
Try it Yourself

🌐 Browser Support

U+2623 is a standard BMP symbol; appearance depends on the font:

Chrome 1+
Firefox 1+
Safari 1+
Edge 12+
Opera 4+
Android 4.4+
iOS Safari 1+

👀 Live Preview

Compare the biohazard sign with the radiation warning (different code point):

Biohazard ☣ U+2623
Large glyph ☣
Radiation (not bio) ☢ U+2622
Label snippet ☣ BIOHAZARD
Monospace refs &#x2623; &#9763; \2623

🧠 How It Works

1

Hexadecimal Code

&#x2623; references code point U+2623 using hex digits 2623 after the #x prefix.

HTML markup
2

Decimal HTML Code

&#9763; is the decimal equivalent (9763) for the same Biohazard sign.

HTML markup
3

CSS Entity

\2623 is the CSS escape for U+2623, used in the content property of ::before or ::after.

CSS stylesheet
=

Same visual result

Hex, decimal, and CSS escapes all produce ☣. There is no named HTML entity for U+2623.

✅

Use Cases

The Biohazard sign (☣) is commonly used for:

🔬 Lab & BSL UI

Intranet pages, door schedules, and training for biosafety levels.

⚠ Warnings & SDS

Online safety data sheets and hazard summaries (with required wording, not icon alone).

🏥 Healthcare

Sharps and regulated waste messaging on portals and digital signage.

♻ Waste & env

Environmental cleanup and industrial hygiene content.

📄 Protocols

SOP HTML exports and lab notebooks published to the web.

🎓 E-learning

Science and workplace safety courses that quiz on hazard symbols.

♿ Accessibility

Always add visible text or aria-label (“Biohazard”); the glyph alone is not enough for compliance or screen readers.

💡 Best Practices

Do

  • Pair ☣ with high-contrast text (for example black on yellow/orange) when mimicking physical labels
  • Use numeric references for stable copy across CMS and email-like HTML contexts
  • Verify the font draws a recognizable trefoil; fall back to SVG or raster if brand guidelines require exact geometry
  • Keep \2623 inside stylesheets only, not pasted into HTML text nodes
  • Follow local law and employer policy for hazard communication; the web page is only one channel

Don’t

  • Confuse U+2623 (bio) with U+2622 (radiation) or other warning pictograms
  • Ship icon-only critical warnings without accessible names or visible hazard class text
  • Assume a tiny grey ☣ in body text meets signage legibility rules
  • Use HTML entities as a legal substitute for approved label PDFs or supplier marks
  • Forget color-blind users: rely on shape and text, not color alone

Key Takeaways

1

Two numeric references render the same glyph

&#x2623; &#9763;
2

CSS content escape

\2623
3

U+2623 is BIOHAZARD SIGN; U+2622 is radiation

4

No &name; entity; plan on hex or decimal in HTML

5

Combine glyph, color, and words to meet real-world hazard communication expectations

❓ Frequently Asked Questions

Use &#x2623; (hex), &#9763; (decimal), or \2623 in CSS content. There is no named entity; all valid methods render ☣.
U+2623 (hex 2623, decimal 9763). Miscellaneous Symbols. Not the same as the radiation sign at U+2622.
When you need the standard biological-hazard pictogram in digital training, intranets, or editorial content—alongside text and in line with your organization’s safety rules.
Numeric references belong in HTML. The \2623 escape belongs in stylesheets (for example on pseudo-elements). Do not paste CSS escapes into HTML text nodes.
No. Use &#x2623;, &#9763;, or \2623 in CSS depending on whether you are authoring markup or styles.

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About the author

Mari Selvan M P
Mari Selvan M P 🔗

Developer, cloud engineer, and technical writer

  • Experience 12 years building web and cloud systems
  • Focus Full Stack Development, AWS, and Developer Education

I write practical tutorials so students and working developers can learn by doing—from databases and APIs to deployment on AWS.

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