Silica Gel Desiccant in Clothing Cartons: Dosage and Placement

Desiccant is the cheapest item in a clothing export carton and the one most often left out. A 40-day sea leg passes through climate zones where the container interior swings between 15 and 45 °C, and the moisture that condenses on hardware, hang tags and adhesive labels is what turns a clean order into a claim. This guide gives a usable dosage table, the desiccant types to avoid, placement rules, and the labelling that EU and Brazilian buyers now check.

1. Desiccant Is a Trims Spec, Not a Freebie

Corrosion and mould do not need a flood — repeated condensation is enough. The parts that fail first are always the same:

Metal hardware such as eyelets, rivets and zipper pulls shows white rust first, and the claim usually costs more than the hardware
Hang tags and folded cartons take up moisture, curl and stop stacking flat, which shows immediately on shelf
Self-adhesive and heat-transfer labels lose tack, barcodes stop scanning at the distribution centre, and chargebacks follow
Once the garment itself moulds, the whole carton is unsaleable — and the money saved on desiccant is long gone

2. How Much Silica Gel: a Working Dosage Table

No single gram figure fits every carton, but grams per cubic metre of carton volume travels across products. Our baseline for garments packed one piece per poly bag: 100 to 150 g per m³ for a 20 to 25 day sea leg, and 200 to 300 g per m³ for 40 days and over, monsoon season or a transhipment route. Add 50 percent if garments sit loose in the carton without an individual bag.

Carton size (cm)	Volume (m³)	20–25 days	40 days and over
50 × 35 × 30	0.05	5 g	10–15 g
55 × 40 × 35	0.08	10 g	20 g
60 × 45 × 40	0.11	15 g	30 g
65 × 45 × 45	0.13	20 g	40 g

Round the result up to a standard sachet: 5 g, 10 g, 20 g, 30 g and 50 g are the sizes normally in stock, so two 10 g sachets are easier to buy than one 15 g.

3. Which Type of Desiccant to Specify

Transparent, non-indicating silica gel — the safe default for Europe and North America: no dye, lowest ingestion risk
Blue indicating silica gel — contains cobalt chloride, a substance of very high concern under REACH; most EU buyers now reject it
Orange indicating silica gel — cobalt-free humidity indicator, slightly dearer, acceptable in most programmes
Montmorillonite clay — cheaper but dusty; white specks show on dark garments
Calcium chloride — strongest absorption but deliquescent; one leak ruins the carton, so never specify it for garments

4. Placement Beats Brand

Where the sachet sits affects the result more than which supplier you buy from. Put one sachet inside the poly bag on top of the folded garment so it works on the air trapped in the bag, then suspend a second one from the inside top of the carton to catch the humid air that rushes in when the box is first opened.

Never lay a sachet directly on leather, silk or dark dyed fabric — oil and dust transfer both ways
Keep sachets clear of sharp hardware such as rivets and zipper teeth that can puncture the paper
In multi-piece cartons put one sachet in each compartment instead of piling them in one corner
Record the count per carton so it can be checked against the shipping mark at inspection

5. Labelling and Compliance: the Sachet Is a Labelled Product

For the EU the obligations come in one package. Product safety under the General Product Safety Regulation GPSR (EU) 2023/988 needs a responsible economic operator established in the EU and traceable identification. The sachet must state, in the destination language, that it is not edible — Trockenmittel – nicht essen in German, sílica gel – não ingerir in Portuguese — plus a keep-away-from-children warning. Where sachets reach the EU together with the goods, check packaging duties under PPWR (EU) 2025/40 and, for Germany, VerpackG registration in LUCID. If the sachet carries an indicator dye, that dye is governed by REACH (EC) No 1907/2006.

One point is regularly missed: neither the sachet nor the packaging may cover the garment's own care label or fibre composition marking. A hidden care label is a labelling defect, not a packing choice.

6. Incoming Inspection: Six Checks

Weigh each sachet; ±5 percent against nominal is the working tolerance
Check the heat-seal line for openings and powder leakage
Confirm the indicator has not turned pink or colourless, which means the stock is saturated
Count per carton against the shipping mark
Confirm food-grade sachet paper or non-woven, with printing that does not touch the contents
Re-seal part-used drums, use within 24 hours of opening, or re-dry at 100 to 120 °C for two hours