What to File When a Botanical Extract Has No CAS Number

You're filling out an ingredient table, you've got the INCI name down for your calendula extract, and then you hit the CAS number column and there's nothing there. Not because you're missing it, but because it genuinely doesn't exist for that ingredient. This happens more often than new filers expect, and the fix isn't to leave it blank and hope, or to invent a plausible-looking number.

Why some botanicals never get a CAS number

CAS numbers are assigned by the Chemical Abstracts Service to identify specific chemical substances. A single, well-defined molecule, like benzyl alcohol or a specific preservative, gets one clean CAS number because it's one specific chemical entity. A botanical extract is different. It's a complex mixture of dozens or hundreds of naturally occurring compounds, and depending on the plant, the extraction method, and the part of the plant used, that mixture can be variable enough that assigning a single CAS number to represent it doesn't work the same way.

Some botanical extracts do have CAS numbers, particularly well-characterized ones or those with a long history of industrial or cosmetic use. Others genuinely don't, and no amount of searching will turn one up because the registry simply hasn't assigned one to that specific extract type.

What to do instead

The INCI name itself is what carries the identification weight when no CAS number exists. The system is built to accommodate this. Correct practice is:

1. Confirm the exact, correct INCI name for your extract, matching the specific plant part and extraction type (leaf extract and root extract from the same plant are different INCI entries, for instance)
2. Leave the CAS field genuinely blank or marked as not assigned, rather than guessing or copying a number from a related but distinct substance
3. Rely on the INCI name as your primary identifier for that ingredient on the filing

Do not, under any circumstance, borrow a CAS number from a similar-sounding ingredient because a form field feels incomplete without one. A CAS number belongs to one specific substance. Attaching the wrong one to your botanical extract creates a real identification error in your filing, one that's arguably worse than leaving the field empty, since it actively misidentifies what's in your product.

A few examples of the pattern

Ingredient type	CAS number situation
A specific, well-defined preservative molecule	Almost always has one clean CAS number
A common, well-characterized botanical extract	May have an assigned CAS number
A less common or highly variable botanical extract	Often has no CAS number, INCI name is the identifier
A supplier's proprietary blend of several botanicals	The blend itself has no CAS number; each individual botanical component might, or might not

That bottom row is worth sitting with. If you're using a supplier's proprietary botanical complex, you need to get the actual composition breakdown from the supplier, INCI name by INCI name, and then check each individual component for a CAS number separately. The blend as a whole never gets its own CAS number, since it's not a registered chemical substance, it's a mixture.

Where people go wrong with trade names

This is closely related to a separate but common mistake: filing a trade name instead of an INCI name at all. Trade names never appear on a cosmetic filing. If your supplier sells you "GreenLeaf Complex," that's a marketing name, and you need to trace it back to its actual INCI-named components before it can go anywhere near your Cosmetic Notification Form. The absence of a CAS number doesn't excuse you from getting the INCI name exactly right, if anything it makes the INCI name more important, since it's doing all the identification work on its own.

Practical steps for sourcing the right information

• Ask your supplier directly for the INCI name and, separately, whether a CAS number exists for that specific extract
• Don't accept a marketing sheet as your only documentation source, ask for the technical or safety data sheet, which should list composition more precisely
• If a supplier can't tell you the correct INCI name for their own ingredient, that's a signal to look elsewhere, since you can't file what you can't properly identify

Getting botanical ingredient identification right is one of the more tedious parts of a cosmetic filing precisely because there's no shortcut, no clean CAS number to fall back on. Cosmetic Comply's ingredient matching is built to handle exactly this kind of case, correctly recognizing when an extract has no CAS number, mapping the INCI name properly, and flagging it clearly on the filing rather than leaving a gap that looks like an oversight.