Short answer
Fill perfume bottles by weight, not by eye: measure the finished perfume's density at 20 °C, convert the label volume to grams, and set a target fill slightly above that so the average is never below what the label says. In the UK and EU, packs from 5 ml up are covered by the "average system" — the average must meet the nominal quantity, only a small proportion may fall short by more than the tolerable negative error (9% for 5–50 ml, 4.5 ml for 50–100 ml), and none by more than twice it. Then fit the pump (crimping it if the neck is a crimp finish), code each bottle with its batch, and keep a fill record with check weights.
Step 1: know the fill weight
Bottles are sold by volume; balances measure mass. The conversion is the density of the finished perfume:
fill weight (g) = nominal volume (ml) × density (g/ml)
Measure the density yourself for each formula, at a controlled temperature — the UK regulations, for example, require volumes to be measured or corrected to 20 °C. The method is in how to measure density, and why weight beats volume throughout perfumery is in perfume weight vs volume. If 50 ml of a perfume weighs 41.00 g at 20 °C, its density is 0.820 g/ml and a 50 ml bottle's nominal fill is 41.00 g.
Step 2: set a target above nominal
Hand filling varies by a few hundredths of a gram or more from bottle to bottle, and some liquid is lost to the dip tube and pump when they are fitted. Aim slightly above the nominal fill so the average stays at or above it. An invented example for the 50 ml bottle above:
- Nominal fill: 41.00 g.
- Target fill: 41.20 g (about 0.5% over).
- Acceptance range at the balance: 41.00–41.40 g. Anything outside is corrected before the pump goes on.
Check the target against the bottle's brimful capacity: it must leave room for the dip tube and pump without overflowing. Overfilling costs money — at a few hundred bottles it adds up — so measure your real variation and tighten the target once you know it.
Check the US customary figure
US labels state net contents in fluid ounces as well as milliliters. 50 ml is 1.69 US fl oz; many labels print 1.7 fl oz, which is 50.3 ml. If your label says 1.7 fl oz, fill to at least that. The same check applies to every size: convert the figure you print back to milliliters and make sure your average reaches it.
The average system (UK and EU)
The UK's Weights and Measures (Packaged Goods) Regulations 2006, and EU rules based on Directive 76/211/EEC, apply to packages of constant nominal quantity from 5 g or 5 ml upward. The packer's three rules are:
- The contents must not be less, on average, than the nominal quantity.
- Only a small proportion of packages may be short by more than the tolerable negative error (TNE).
- No package may be short by more than twice the TNE.
| Nominal quantity | TNE | Example |
|---|---|---|
| 5 to 50 ml | 9% of nominal | 30 ml: 2.7 ml; 10 ml: 0.9 ml |
| 50 to 100 ml | 4.5 ml | 50, 75 or 100 ml: 4.5 ml |
| 100 to 200 ml | 4.5% of nominal | 150 ml: 6.75, rounded up to 6.8 ml |
| 200 to 300 ml | 9 ml | 250 ml: 9 ml |
Percentage TNEs are rounded up to the nearest 0.1 g or ml. For the 50 ml example, the TNE is 4.5 ml — 3.69 g at 0.820 g/ml — so no bottle may contain less than 41.00 − 2 × 3.69 = 33.62 g, and very few may contain less than 37.31 g. A filling process aimed at 41.20 g is nowhere near those limits; the rules mainly catch careless processes and wrong densities. Packers must keep records of their checks and use equipment suitable for them. The ℮ mark printed next to the quantity is a packer's voluntary declaration that the packs comply with the average system; use it only if they do.
Sample vials under 5 ml are outside these regulations, but still fill them by weight; see how to make perfume samples.
Step 3: fill
- Confirm the perfume batch is released: rested, filtered if your process requires it, and checked. Record its batch number.
- Check the balance with a reference weight; record it.
- Inspect bottles for chips and dirt; blow out dust if needed.
- Tare a bottle, fill to the target with a pipette, syringe or dispenser, and read the weight. Weigh every bottle when filling by hand.
- Fit the dip tube and pump without spilling. For crimp necks, crimp with a tool set for that neck and pump, and check the crimp is tight and the glass is undamaged on the first bottles and at intervals. Components are covered in perfume packaging components.
- Fit collars and caps; wipe bottles.
- Label with the batch code (batch numbers and lot codes) and reconcile labels: labels issued = labels used + labels spoiled + labels returned.
- Set aside retained samples from the filled batch.
The fill record
Record: product and size, perfume batch, density used, target and acceptance range, balance check, component lots, number filled, rejects and why, a list or summary of fill weights (at least the average, lowest and highest), label reconciliation, retained samples, date and initials. It belongs with the batch record (perfume batch records) and is the evidence that your packs meet the quantity on the label. A written procedure makes it repeatable; see perfume lab SOPs.
Filling is the last step of making a perfume in the lab described in how to organize a perfume lab.
Sources
- legislation.gov.uk — The Weights and Measures (Packaged Goods) Regulations 2006, Schedule 3 (tolerable negative errors and rounding); regulation 3 (scope, 5 g or ml to 25 kg or l); Schedule 2 (volumes at 20 °C); checked October 10, 2026.
- GOV.UK — Packaged goods: weights and measures regulations, the three packers' rules, the ℮ mark and record-keeping; checked October 10, 2026 (page updated September 20, 2024).
- EUR-Lex — Council Directive 76/211/EEC on prepackaged products; checked October 10, 2026 (link format).
- eCFR — 21 CFR 701.13, net quantity of contents of cosmetics; checked October 10, 2026 (link format).
Frequently asked questions
Can I fill to a line on the bottle instead?
Fill lines vary with glass thickness and are hard to read consistently. Weighing is faster once set up and gives you the record that proves the quantity.
Should the target change between batches?
Only if the density changes — for example after a formula change. Re-measure density for each new formula version and check it occasionally on production batches.
What if a bottle is under the acceptance range after the pump is crimped?
Set it aside. A crimped pump cannot be removed and refitted reliably; record it as a reject and look at why it happened.
Written and reviewed by the RUŌOD Lab team. This article is general education about perfume formulation and record-keeping; it is not legal, regulatory or safety advice, and the examples are illustrations, not validated commercial formulas. How we write and check these guides.