Why Version a Formula?
"I changed the formula a little" is the most expensive sentence in perfume production. If a change was made but not recorded, then a year later, when a customer says "the old scent was better", nobody knows what the old scent was. Which formula was the IFRA certificate issued for? Which proportions was the allergen declaration calculated on? Which version was the stability test run on?
Formula versioning means numbering every change to an approved formula and recording it together with its rationale and its effects. Change control is the process of evaluating and approving that change before it is made. Together they keep the question "which lot was made with which formula" answerable at all times.
This system is not for mods at the development stage; mods are free. Versioning starts the moment a formula goes into production.
Version Number: Major and Minor Changes
A simple and sufficient system has two digits: Vmajor.minor. The major digit is for changes that alter the scent, the minor digit for changes that do not.
| Type of change | Example | Version | Checks required |
|---|---|---|---|
| Minor: scent unchanged, composition changed for a practical reason | Different dilution of the same molecule; solvent brand; rounding correction | V1.0 → V1.1 | Weighing list, cost |
| Minor: equivalent raw material substitution | Same CAS, different supplier; same quality natural oil, different origin | V1.1 → V1.2 | Triangle test, density, short stability test |
| Major: change in proportion | Hedione 8% → 12%; musk base increased | V1.x → V2.0 | IFRA, allergens, stability, compatibility, cost, customer approval |
| Major: raw material replaced | Lilial removed, another molecule put in its place | V2.x → V3.0 | All of the above + regulatory check |
Every version has its own IFRA and allergen calculation; even if the result comes out the same for a minor change, the calculation is redone and filed under the version number. The link between document and formula is the version number.
The product name does not change; the version number is invisible to the customer. What the customer knows is "Vetiver EDT"; what you know is "Vetiver EDT V2.3", and that number appears in every lot record.
Change Control: Step by Step
Change control puts a form between "let's change it" and "we changed it". The form can be short; what matters is that every step has an answer and a signature.
- Request and rationale
Who wants to change what, and why? "Raw material X cannot be sourced", "the customer wants more longevity", "the IFRA amendment lowered the limit". There is no change without a rationale.
- Impact assessment
What does the change affect: scent, IFRA compliance, allergen declaration, label, stability, base compatibility, cost, regulation. For each heading, write "not affected" or "this test is required".
- Trial and testing
The new version is prepared in a small batch; the tests set out in the impact assessment are run. For a major change, a triangle test and short stability are the minimum.
- Approval
The responsible person approves (in a small business this is often one person, but still in writing). For a customer-specific formula, customer approval is obtained and filed.
- Update the documents
The new version's formula sheet, IFRA and allergen calculation, weighing list, cost card. The old version is marked "archive", not deleted.
- Set the effective lot
"V2.0 is effective from batch number 2026-0412." This line fixes for ever which lot was made with which version.
- Manage stock
If there is product made with the old version or labels already printed, write down what happens to them: sold, relabelled or withdrawn.
Archive and Traceability: From Lot Back to Formula
The system's test is a single question: "Which formula was this bottle made with?" The answer must be found in three steps: the batch number on the bottle, the version number in the batch record, the formula sheet in the version archive. If it cannot be found in three minutes, the system is not working.
For each version the archive holds: the formula (as pure substances and as a weighing list), the raw material lots with which it was first validated, the IFRA and allergen calculation, stability and compatibility results, the change control form, the effective date and lot, the approval. Old versions are not deleted; they are marked "V1.0 – valid 03.2024 – 11.2025".
In a digital archive, the file name carries the version number and the file is write-protected. In a paper archive, each version is a separate sheet, with version and date at the top of the page. In a spreadsheet, each version is a separate tab; overwriting a single tab called "current" is the exact opposite of versioning.
For customer-specific formulas the archive doubles: the version the customer approved and the approval letter are filed together. When the customer says a year later "we never approved this", the answer is in the archive.
Frequently Asked Questions
The most common questions about formula versioning.
I run a small business and I am the only formulator; do I still need this?
I changed supplier for a molecule with the same CAS number; should I open a version?
Where exactly is the line between a mod and a version?
Can I keep selling product made with the old version?
Should I put the version number on the label?
Does the customer have to know about a formula change?
What happens when an IFRA amendment arrives?
Which software should I use?
Related articles
Batch Numbers & Production Record-Keeping for Fragrance Makers
Consistency is the hallmark of a serious fragrance maker. Learn how to assign batch numbers, build a production logbook, and create a fully traceable record for every batch you produce.
Read →IFRA Amendment Transitions: How to Stay on Top of Evolving Fragrance Standards
IFRA Standards are not set in stone — each amendment can restrict, reduce, or ban ingredients you use today. Here is how to read the timelines, understand real-world bans, and build a compliance routine that keeps your formulas permanently up to date.
Read →How to Prepare a PIF (Product Information File) for Cosmetics
A Product Information File (PIF) is the mandatory technical dossier every cosmetic brand must maintain before placing a product on the market. Learn exactly what goes inside one and how to build yours step by step.
Read →