FD&C, AC, and What They Actually Mean
If you have ever looked at ingredient labels and wondered why the same dye seems to have multiple names, you are not alone. This confusion is common — and it exists because dyes are named differently depending on who is doing the labeling and why.
This page explains those names in plain English.
The Short Answer
It is often the same dye, just listed under different naming systems.
For example:
Red 40
FD&C Red No. 40
Allura Red AC
All three names refer to the same artificial dye.
What “FD&C” Means
FD&C stands for Food, Drug, and Cosmetic.
When you see FD&C in an ingredient name, it means:
• The dye has been reviewed and approved by the U.S. Food and Drug Administration
• It is allowed to be used in foods, medications, and cosmetics
• It has passed FDA certification for those uses
So when you see:
FD&C Red No. 40
That is the regulatory approval name — the name used in official U.S. ingredient labeling.
Think of FD&C as the dye’s legal name in the United States.
What “AC” Means
AC stands for Allura Color.
Allura Red AC is the scientific and international name for the same dye Americans usually call Red 40.
This name is commonly used in:
• Scientific research
• International ingredient lists
• Technical and chemical references
So:
Allura Red AC = Red 40 = FD&C Red No. 40
Different name. Same substance.
Why Dyes Have Multiple Names
Artificial dyes often appear under different names because they are labeled for different audiences.
• Food packaging may use a simple consumer name
• Medication labels may use a regulatory name
• Scientific sources may use a chemical or international name
None of these names are wrong. They are just different labels for the same ingredient.
Why This Causes Confusion
Many people try to avoid certain dyes by watching food labels.
But if the same dye appears in medication under a different name, it may not be recognized.
For example, someone avoiding “Red 40” in food may not realize they are still exposed when a medication lists:
FD&C Red No. 40
or
Allura Red AC
This is one reason ingredient awareness can be difficult without tools that recognize all naming variations.
Why This Matters for Sensitive Individuals
Artificial dyes do not affect everyone the same way.
Some people report sensitivities that may include:
• Behavioral changes
• Headaches or migraines
• Skin reactions
• Respiratory symptoms
For these individuals, recognizing all names for the same dye can matter.
The Takeaway
Different names do not mean different dyes.
They usually mean:
• Regulatory name
• Scientific name
• Consumer-friendly name
All pointing to the same ingredient.
Understanding naming differences helps close the gap between what people think they are avoiding and what they may still be encountering.
Related Reading
• Artificial Dyes in Medicine and Food
• Common Artificial Dyes – Quick Reference