P-4000

P-4000 was an artificial sweetener roughly four thousand times as sweet as sugar, which is where the name comes from. The FDA prohibited it in 1950, in the same period it acted against dulcin, and it has had no food use since.

Where it is and isn’t permitted

Status of P-4000 by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
United StatesFood and Drug AdministrationProhibited21 CFR 189.175retrieved 2026-09-07
Codex AlimentariusCodex Alimentarius Commission / JECFANot listedDoes not appear on this jurisdiction’s permitted list. That is not the same as being prohibited.

What it is made from

A synthetic aromatic compound, 5-nitro-2-propoxyaniline, made from petroleum-derived starting materials. It is of historical interest only; nothing in the food supply contains it.

  • Vegan
  • Vegetarian
InChIKey
RXQCEGOUSFBKPI-UHFFFAOYSA-N
PubChem
CID 11118

Every name it appears under

29 recorded names. A label may use any of them.

CAS registry number

  • 553-79-7

As it appears in regulation

  • P-4000

Other names

  • 1-n-Propoxy-2-amino-4-nitrobenzene
  • 1-Oxy-2-amino-4-nitrobenzol propyl aether
  • 1-Propoxy-2-amino-4-nitrobenzene
  • 1-Propoxy-2-amino-4-nitrobenzol
  • 2-Amino-4-nitro-1-n-propoxybenzene
  • 2-Amino-4-nitro-1-propoxybenzene
  • 5-Nitro-2-n-propoxyaniline
  • 5-NITRO-2-PROPOXY ANILINE
  • 5-Nitro-2-propoxy-Aniline
  • 5-Nitro-2-propoxy-Benzenamine
  • 5-Nitro-2-propoxy-phenylamine
  • 5-Nitro-2-propoxyaniline
  • 5-Nitro-2-propoxybenzenamine
  • 5-Nitro-2-propoxyphenylamine
  • ANILINE, 5-NITRO-2-PROPOXY-
  • Aros X
  • Aros-X
  • Benzenamine, 5-nitro-2-propoxy-
  • Benzenamine, 5-nitro-2-propoxy- (9CI)
  • BRN 2098543
  • HDS42MR6BM
  • P 4000 (Sweetener)
  • Sweetening agent P 4000
  • Sweetening Agent P-4000
  • Ultrasuess
  • Ultrasuss
  • Ultrasweet

Hazard reference values

No reference value for this substance in the sources we hold.

Evidence and how bodies read it

Studies, and the differing conclusions regulators drew from them, are curated by hand rather than machine-read, and none has been written for this substance yet.

Sources for this page

  • ecfr retrieved 2026-09-07

Full licence terms and publisher details on Sources. How this page is built and updated: Method.

Machine-readable:/api/v1/additives/p-4000.json