Perfumers Codex is a small reference for the raw materials perfumers work with, where each fact links to the document it came from. This page explains what you are looking at on a material page, where each part comes from, and what the site does not do.
A material is one ingredient you can buy and weigh out at the bench. Each one has its own page, and the small label above its name says which of three kinds it is:
The catalogue is small on purpose. A material appears only after I have reviewed everything its page shows, so it grows slowly, and depth comes before coverage.
Below that, Names and identifiers folds away the rest: trade names, supplier names, other names, abbreviations and systematic names. One molecule is often sold under many names, and each name here cites the document it came from. No name is added without one.
A description of how the material smells, written by hand at the bench. Descriptions are never generated by software.
Not every page has all of these yet. When a description carries no citation, the page says it was written from my own bench experience. Read it as one perfumer’s impression, not a measurement: noses differ, and a material can smell quite different at different dilutions and in different company.
IFRA, the International Fragrance Association, is the fragrance industry’s self-regulatory body. Its Standards limit how much of an ingredient may be used, ban it, or set conditions on it, depending on the kind of product it goes into.
Categories. IFRA sorts products by how they touch the body: lip products are Category 1, deodorants Category 2, fine fragrance (perfume, eau de toilette, cologne) Category 4, rinse-off soaps and shampoos Category 9, and products not meant to touch the skin, such as candles, Category 12. Some categories are split into lettered subcategories with limits of their own: 5A to 5D, 7A and 7B, 10A and 10B, 11A and 11B. Body lotions (5A) and baby creams (5D), for example, can carry very different limits for the same material.
The table has one row for each category or subcategory, under the code IFRA prints in the Standard, with IFRA’s description of the products it covers. Use the row for the product you are actually making. Category 4 is highlighted because it is the row most readers look for first.
The limit is the highest share of the material allowed in the finished product: the perfume or lotion as it is sold, not your fragrance concentrate. If your concentrate makes up 20% of a finished perfume and a material is 10% of the concentrate, the finished perfume contains 2% of that material. That 2% is the number to compare with the limit.
Amendment and verified date. IFRA revises its Standards in numbered amendments. The badge names the amendment that issued the Standard. A Standard stays in force through later amendments until IFRA revises it, so an older number is not necessarily out of date. The verified date is when the limit was last checked against IFRA’s own documents.
“No IFRA Standard” means the complete index of Standards for the named amendment was checked and this material is not in it. It is a statement about that amendment, not a statement that the material is safe at any dose. “No IFRA limits recorded yet” is different: it means nobody has checked.
GHS, the Globally Harmonized System, gives each kind of hazard a code, such as H317, “may cause an allergic skin reaction”. Each code on a page cites the safety data sheet or classification it came from. When companies classify a material differently, only the classification most of them agree on is recorded.
“No GHS hazard codes recorded” does not mean a material is free of hazards. Every safety section ends with the same line, and it is the most important one on the site:
This page is a reference, not a regulatory authority. Check the current IFRA standard and the supplier’s safety data sheet before you formulate.
The small numbers after a fact, like [2], link to the Sources list at the foot of the page. Each entry gives the document’s title, what kind of source it is (an IFRA Standard, a safety data sheet, PubChem, a manufacturer’s page and so on), and the date it was accessed.
Identity, names, IFRA limits, “No IFRA Standard” findings, GHS hazards and landmark uses must each carry a source: the database refuses them without one. Olfactive descriptions and usage guidance may be uncited, and when they are, the page says they come from my own bench experience.
Cited facts are researched from primary sources with the help of AI agents. Each fact is then checked again against its source by two independent checks that try to disprove it, and is kept only if both confirm it; nothing is taken from an AI model’s memory. I review the whole page before it is published, and if anything it shows changes later, the page is hidden until I review it again.
If you find a mistake, corrections with a source behind them are welcome; the terms say how to send one.
Below the main sections, some pages show values worked out from the structure by RDKit, labelled with the RDKit version that produced them. They are calculations, not measurements and not cited facts, and none of them tells you how a material smells or how long it lasts.
Structurally similar compares the molecule with the other published materials and scores how many structural fragments they share, from 0 (none) to 1 (identical). Scores below 0.3 are noise and are not shown; 0.3 to 0.5 is distantly related, 0.5 to 0.7 related, and 0.7 or more a close analogue. With a small catalogue, most pages have no neighbour above 0.3, so the section does not appear.
Similar structure does not mean similar smell. Molecules that look almost identical on paper can smell nothing alike, and molecules that smell alike can look nothing alike.
A page may one day carry a box labelled Experimental with predicted odor descriptors. That would be the output of a computer model, kept apart from the description and never presented as one. No page shows it today.
You don’t need an account to read anything. With one, you can bookmark materials and keep a private note on each. Notes are visible only to you and never appear beside the cited facts. The privacy policy and the terms cover the rest.