Garbing order is one of the few parts of sterile compounding where the sequence matters more than the product. You can buy the best sterile gown on the market and still contaminate it by putting it on before your hair cover. USP General Chapter <797> sets the order deliberately: you work from the dirtiest part of the body downward and outward, you do it in the anteroom, and you cross the line of demarcation only once you are clean.
We make and pack the garb itself, which means we see the failures from the other end — the returns, the complaint calls, the photos of a torn cuff or a gown that shed on the first wear. What follows is the order USP sets out, with the specification that matters at each step and the thing that most often goes wrong on the floor.
Where garbing happens: the anteroom and the line of demarcation
An ISO 7 anteroom is held at no more than 352,000 particles ≥0.5 µm per cubic metre at rest, per ISO 14644-1. The buffer room beyond it is also ISO 7 when it feeds an ISO 5 primary engineering control. The anteroom floor is split by a line of demarcation: the dirty side, where street clothes and shoes are, and the clean side, where garbed personnel stand. Everything from shoe covers through the gown goes on on the dirty side, one foot at a time crossing over as it is covered. Hand hygiene and sterile gloves happen on the clean side.
Pharmacies that lose this distinction almost always lose it the same way: there is no physical line, just an understanding of where it used to be. Paint it, tape it, or set a bench across it. An inspector will ask.
The order, step by step
| # | Item | Side of the line | Specification that matters | What goes wrong |
|---|---|---|---|---|
| 1 | Shoe or boot covers | Dirty → step over | Non-skid sole, low-lint non-woven, 40–50 gsm; boot height for hazardous areas | Both covers applied standing on the dirty side, then both feet crossing together — defeats the point |
| 2 | Bouffant cap, then beard cover | Dirty side | 21–24 in bouffant for full coverage; latex-free elastic; no exposed hairline | Undersized bouffant riding above the hairline; sideburns and nape left out |
| 3 | Face mask (and eye protection where required) | Dirty side | 3-ply with meltblown middle layer; nose wire; ties or ear loops that survive a shift | Mask pulled down to talk, then pulled back up with gloved hands later in the process |
| 4 | Hand hygiene: wash to the elbow, dry with low-lint towels | Clean side | 30 s minimum with soap and warm water; dry completely before gowning | Paper towels that shed; damp forearms transferring into gown sleeves |
| 5 | Gown, frock or coverall | Clean side | Low-lint SMS or microporous film; knit or elastic cuffs; rear closure; ASTM F1671 barrier for hazardous work | Cuffs stretched out over repeated wears, so the glove no longer seals over them |
| 6 | Alcohol-based hand rub, allowed to dry | Clean side | Full dry time before gloves — typically 20–30 s | Gloves donned on wet hands; the rub never contacts the skin it was meant to |
| 7 | Sterile gloves | Buffer room | Sterile, powder-free nitrile; 12 in cuff to cover the gown cuff; ASTM D6978 permeation data for hazardous work | Exam-grade gloves substituted for sterile; cuff too short to overlap the sleeve |
| 8 | Sterile 70% IPA on gloved hands, repeated at the hood | Buffer room / ISO 5 | Sterile-filtered, 0.2 µm, lot-certified; reapplied after every contact with a non-sterile surface | Non-sterile IPA from the general supply closet used inside ISO 5 |
Where hazardous compounding changes the order
For hazardous handling under USP <800>, the sequence is the same but three items change grade. The gown must be a tested barrier — ASTM F1671 viral penetration resistance, back-closing, with no seams or closures that can wick. Gloves are doubled: one pair under the gown cuff and one over it, both with ASTM D6978 chemotherapy permeation data on the certificate, and the outer pair changed every 30 minutes or immediately on contamination. Sleeve covers go on over the gown cuff where there is any risk of splash at the wrist. Everything comes off in reverse order, outer glove first, inside the negative-pressure room, and goes straight into the hazardous waste stream rather than the regular bin.
The failure we hear about most on hazardous orders is not a garbing error at all — it is a documentation one. A buyer orders “chemo gloves,” receives a nitrile glove that meets ASTM D6319 for exam use, and has nothing to show an inspector because D6319 says nothing about permeation. Ask for the D6978 report by lot, not a marketing claim. We ship it with the order.
What we hold on the garb we make
Three things determine whether a garment behaves in an ISO 7 room: lint, barrier and fit. Lint is the one buyers underestimate. A spunbond-meltblown-spunbond gown at 45–50 gsm with ultrasonically bonded seams sheds far less than a stitched gown of the same weight, because every needle hole is a particle source. We specify ultrasonic or heat-sealed seams on anything going into a buffer room, and we Helmke-drum test the fabric lots rather than taking the mill's word for it.
Barrier is a function of the film or the laminate, not the gsm. A heavier non-woven gown is not automatically a better barrier; a 40 gsm microporous laminate can outperform a 60 gsm SMS. Fit is the quiet one — a gown that is too small pulls the cuff up the forearm the first time someone reaches into a hood, and a gown that is too large bunches at the elbow and drags across the work surface. Order two sizes and let the staff pick; the cost difference is trivial against one contaminated preparation.
Sterile garb is terminally gamma-irradiated to a validated 10-6 sterility assurance level and double-bagged, inner bag opened only on the clean side. If the inner bag is opened on the dirty side of the line, the garment is no longer sterile no matter what the label says.
Building the kit
Most pharmacies buy garb one item at a time from three different distributors and end up with a bouffant that does not match the beard cover and a gown cuff that does not seal under the glove. It is worth specifying the set together. Our full list of cleanroom and garbing supplies is organised the way the rooms are, and the companion guide on what to stock by room covers the surface disinfectants, wipes and monitoring consumables that sit alongside it. For hazardous programmes, the USP 800 supplies page lists the tested-barrier versions of each item.
If you send us your room classifications, headcount and whether you compound hazardous preparations, we will put a garbing kit together against them and quote it factory-direct, with the test certificates attached. Request a quote and we will come back within one business day.