P-4000

CAS 553-79-7

Listed as a sweetener by the US.

Listed as sweeteners (US)
Chemical structure of P-4000, from PubChem compound 11118
Structure from PubChem CID 11118 (National Library of Medicine, public domain). A depiction of one compound: where a listing covers a family, or a substance has no single structure, this page shows none.

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
Australia and New ZealandFood Standards Australia New ZealandNo listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it.
CanadaHealth CanadaNo listing matchedHealth Canada’s lists name additives without E or INS numbers, so this site matches them by exact name. A substance listed there under a name this site does not recognise has no row here.
European UnionEuropean Commission / EFSANo listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it.
Great BritainFood Standards Agency / Food Standards ScotlandNo listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it.
JapanConsumer Affairs AgencyNo listing matchedThis site imports only Japan’s list of designated additives (Appended Table 1 to the Regulations for Enforcement of the Food Sanitation Act), matched by English name. Existing additives, natural flavouring agents and ordinary foods used as additives are permitted outside that list and are not imported, so an empty row does not show that Japan does not permit the substance.
South KoreaMinistry of Food and Drug SafetyNo listing matchedThis site imports Part III of South Korea’s Standards and Specifications for Food Additives, matched by CAS number, then INS number, then exact name. Mixed preparations and sanitisers are not imported, and an entry whose identifiers disagreed with a page’s is held for review, so an empty row does not show that South Korea does not permit the substance.
United StatesFood and Drug AdministrationProhibited21 CFR 189.175retrieved 2026-10-17
Codex AlimentariusCodex Alimentarius Commission / JECFANot listedDoes not appear on this jurisdiction’s permitted list. That is not the same as being prohibited.

What a label must say

Words a food containing P-4000 is obliged to carry, quoted from the instrument that imposes them. A required statement is a fact about the regulation, not a finding about the substance — every rule below applies where the additive is authorised.

Every rule collected at what a label must say.

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

Compare other additives on the dietary indexes.

CAS registry number
553-79-7
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 rather than machine-read, and none has been written for this substance yet.

Common questions

Assembled from what is above, in the words the questions are usually asked in. Each answer is the same statement the relevant section makes, with the same citations behind it.

What is 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.
What is P-4000 used for in food?
It is listed as a sweetener — the role the US assigns it. This page shows every function each regulator records, with the citation for each.
Is P-4000 vegan?
Yes. P-4000 is not derived from animals, and is suitable for vegetarians. This page says what it is made from and how.

Sources for this page

  • ecfr retrieved 2026-10-17

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

Machine-readable: a JSON record of this additive is given on request —how to ask for access.

Follow changes to P-4000:Atom feed — regulatory events, and any change the weekly refresh detects in its provisions.