In pharmaceuticals, quality and patient safety are contamination-control problems disguised as “operations” problems. In sterile compounding environments, the purpose of USP <797> is to reduce preventable patient harm by controlling contamination risks like microbial contamination, excessive endotoxins, and ingredient/process variability. The “fix” is rarely a heroic cleaning event. It is a repeatable method: controlled tools (swabs and low-linting wipers), controlled chemistries (sterile alcohol where required), disciplined glove changes, and a setup that prevents recontamination. USP <797> overview
- “We clean, but microbial recoveries keep returning”: method drift (wetness, wipe-face control, contact time, staging) and recontamination pathways are still active. Fix: lock the method and the zone boundary, and standardize execution.
- “Surfaces look clean, but we still fail residue expectations”: film and chemistry mismatch. Fix: use chemistry designed for cleanrooms, control application/removal, and define what “done” looks like under the right lighting.
- “We keep chasing investigations”: uncontrolled substitutions (tools/chemistry) and weak documentation. Fix: stabilize the consumables list and align logs/checklists to the work.
- “Alcohol is causing overspray and variability”: spray habits create uncontrolled wetness and re-deposit. Fix: controlled dispensing + tool application (wiper/swab) and defined triggers.
SOSCleanroom supports critical environments with best-in-class cleanroom consumables (wipers, swabs, gloves, solutions) and practical education resources used in medical and pharmaceutical settings. The business is operated by Specialty Optical Systems (SOS), founded in 1981, with a long track record supporting controlled environments where reliability and contamination control are non-negotiable. About SOSCleanroom
Not every pharmaceutical operation requires the same level of cleanroom classification, but many benefit from disciplined controlled environments around open handling, staging, and high-touch interfaces. Cleanrooms are designed for tighter contamination control; controlled environments still reduce variation and prevent the most common root causes of repeat deviations: (1) particles/fibers, (2) residues/films, and (3) viable contamination pathways. Cleanrooms vs. controlled environments
- Material transfer and staging surfaces
- High-touch interfaces (handles, carts, control panels)
- Between-batch / between-operation cleaning where recontamination is common
- Alcohol disinfection steps and rotation disinfectant steps (per SOP)
- Equipment exteriors, pass-throughs, and carts
- Floors, walls, and high-touch zones where drift accumulates
- Maintenance intrusions and changeovers (big recontamination moments)
- Residue-sensitive benches and hoods
- Controlled sampling and transport steps for monitoring/validation
- Swabbing workflows where background control matters
Risk statement: Contamination control is ultimately a risk-management problem: you are controlling nonviable contamination (particles/fibers), chemical residues/films, and viable contamination across products, processes, and people—under a defined quality scope.
- ISO (measurement framework): particle classification and control language used across industries.
- Annex 1 (sterile “playbook”): expectations for sterile medicinal products and an explicit Contamination Control Strategy (CCS) mindset.
- Practical takeaway: measurement + method discipline + documentation produce repeatable, safer manufacturing.
- Zone boundary discipline: control what enters; remove corrugate/shipping cartons from critical boundaries.
- Surface control: cleaning is a method—not a label—chemistry + coverage + technique + contact/dry time (where applicable).
- Evidence of control: define when cleaning occurs, what tools are approved, and what “done” looks like (plus logs/checklists).
This section is written to help operators and supervisors connect recurring observations to the most common contamination pathways—and to the method controls that address them.
- Recurring microbial recoveries: recontamination after cleaning, inconsistent wetness/contact time, or uncontrolled touch events.
- Endotoxin/bioburden concerns: mismatch of chemistry to risk, inconsistent execution, or uncontrolled water/solution inputs where regulated grades are expected.
- Haze, streaking, or residue films: chemistry mismatch, over-wetting, reusing loaded wipe faces, or leaving behind non-volatile residues.
- Particle/fiber findings: shedding tools, corrugate near the zone boundary, or uncontrolled wipes/paper products.
- “It passes today but fails tomorrow”: method drift—different operators, different wetness, different tool use, different timing.
Selection is driven by shedding risk, chemistry compatibility, and geometry. For residues, sampling, and tight interfaces, choose tools that minimize background and allow controlled contact. (No wiper or swab is universally “lint-free” in every condition; the goal is low contamination appropriate to the process.)
- Low-linting cleanroom wipers: routine surface wipe-down, equipment exteriors, and controlled chemistry application/removal.
- Sterile wipers (where required): aseptic/sterile suites and approved sterile workflows.
- Pre-wetted wipers: when wetness control and repeatability are priorities and chemistry is compatible with the method.
- Cleaning and precision interfaces: corners, seams, ports, and small features where a wiper cannot control contact.
- Validation/surface sampling: swabs engineered for controlled background when sampling results must be defensible.
- Transport workflows: sterile swab-and-tube formats that support controlled collection and transport to the lab.
- Gloves reduce transfer—but only if operators change them at defined triggers (doors, carts, cartons/corrugate, phones, keyboards, trash).
- Touch habits drive variation: “quick touches” create recontamination, especially at staging and high-touch interfaces.
- Sterile nitrile options support sterile suite workflows where sterile gloves are part of the approved method.
- Fold discipline: manage wipe faces intentionally; change faces frequently rather than spreading soils across a larger area.
- One-direction strokes (where applicable): reduce re-deposit and streaking on residue-sensitive surfaces.
- Wetness control: control application; avoid flooding seams and hard-to-access features.
- Swab discipline: do not re-dip a used swab into the main container; dispense into a controlled secondary container and discard on a defined cadence.
In pharmaceutical environments, disinfectants and alcohol are used to manage microbial risk—but poor control can create new failure modes: overspray, residue films, inconsistent contact time, and operator-to-operator variability. The goal is repeatable risk control: manage particles, residues, viable contamination, and documentation defensibility without creating new variability.
USP <797> cleaning product guidance hosted on SOSCleanroom.com describes sterile 70% isopropyl alcohol use for wiping supplies removed from shipping cartons and for wiping hard surfaces prior to compounding, along with broader cleaning and disinfection steps.
- Hydrogen peroxide (H₂O₂) is positioned on SOSCleanroom.com as a core chemistry in many cleanroom rotation programs because it delivers strong microbial control and breaks down into water and oxygen, supporting low-residue disinfection strategies.
- Sterile 6% formats are described as ready-to-use for cleaning surfaces and equipment in pharmaceutical, biotech, and medical device cleanrooms where a sterile hydrogen peroxide solution is required.
- SOSCleanroom notes that facilities use DI/high-purity water for general cleanroom cleaning and rinsing.
- For regulated manufacturing, SOSCleanroom highlights USP Purified Water (PW) or Water for Injection (WFI) when pharmacopeial quality is required.
- SOSCleanroom also notes sterile purified water formats for point-of-use cleaning where USP PW is required, with higher-grade operations stepping up to WFI per SOP.
This section is written at the operator level. Always follow approved SOPs and validated chemistries. The goal here is to reduce variation and prevent the most common handling errors that reintroduce contamination. Cleanroom cleaning overview
- Prepare the zone: clean the staging surface; remove corrugate and uncontrolled paper sources from the boundary.
- Glove up: use approved gloves; define re-glove triggers before touching critical surfaces.
- Control wetness: dispense chemistry into a controlled container; dampen the tool (avoid dripping).
- Coverage + direction: use the defined stroke pattern (often one direction) and clean-to-dirty logic.
- Change faces: do not reuse a loaded wipe face; switch to a clean face or a fresh tool.
- Stop conditions: if you see haze, streaking, or fibers, stop and reset tools/chemistry instead of continuing.
- Use swabs: a wiper cannot reliably control contact in tight features.
- Do not re-dip: dispense into a controlled secondary container; discard swabs on a defined cadence.
- Rotate the swab head: use a clean surface as you work to avoid re-deposit.
- Define cleaning cadence for handles, carts, keyboards, and touchscreens.
- Lock glove-change triggers and enforce them consistently.
- Use checklists: what gets cleaned, when, with what chemistry, and what “done” looks like.
Annex 1 expectations emphasize an explicit contamination-control approach (CCS mindset) in sterile environments. In practice, many failures come from “in-between moments”: transfers, staging, and uncontrolled boundary crossings. Annex 1 overview
- Material transfer: keep shipping cartons outside; stage cleanly; use double-bagged/controlled formats where required.
- Alcohol formats: sterile ethanol and sterile IPA product formats are described on SOSCleanroom.com as 0.2 µm filtered, double-bagged, and gamma-irradiated options designed for sterile cleanroom use.
- Boundary discipline: define what can enter the zone and how it is wiped/introduced.
SOSCleanroom does not author your SOPs. The modules below are suggested templates your team can adapt, approve, and validate within your own quality system. The purpose is to remove variation across operators and shifts.
- Remove corrugate/shipping cartons and uncontrolled paper sources from the zone boundary.
- Wipe staging surfaces with approved wiper + approved chemistry; allow dry/contact time as required.
- Stage only approved swabs/wipers/gloves and controlled dispensing containers.
- Confirm waste container and discard rules for used tools.
- Define chemistry, wetness level, stroke pattern, and maximum passes.
- Define wipe-face control and discard rules (no reuse of loaded faces).
- Define “stop conditions” (haze, streaking, visible fibers) and escalation path.
- Define routine chemistry and periodic rotation chemistry (as applicable to your validated program).
- Define where rotation applies (floors, walls, high-touch, critical surfaces) and required contact times.
- Define documentation: lot traceability, prep/dilution records (if any), and completion logs.
- Define re-glove triggers: doors, carts, corrugate, phones, keyboards, trash, outside-touch events.
- Define “no bare hands” rules in controlled zones and near critical interfaces.
- Define what can enter the zone (approved tools only) and how tools are staged between uses.
- Dispense approved chemistry into a controlled secondary container.
- Dampen the swab (not dripping). Do not spray toward open interfaces.
- Wipe the corner with a controlled motion; rotate swab head to a clean surface.
- Discard the swab. Do not re-dip used swabs into the main container.
- Perform a visual check under defined lighting before release.
- Define the zone boundary: what enters and what stays out (corrugate, uncontrolled wipes, uncontrolled spray bottles).
- Lock the consumables list: approved swabs, wipers, gloves, and chemistry delivery formats by task and zone.
- Provide SOP suggestions: standardized wording and checklists your team can incorporate into approved procedures.
- Reduce substitution risk: stable procurement choices aligned to validated use cases (so teams aren’t forced into unqualified changes).
- SOSCleanroom USP <797> educational overview and related hosted materials (sterile compounding intent and contamination risks). View
- SOSCleanroom ISO vs. Annex 1 educational guidance (ISO measurement framework + Annex 1 CCS mindset). View
- USP <797> Cleaning Products brochure hosted on SOSCleanroom.com (sterile 70% IPA use and cleaning/disinfection context). View PDF
- SOSCleanroom purified water guidance for cleanrooms (DI/high-purity, USP PW, and WFI context). View
- SOSCleanroom hydrogen peroxide guidance and sterile 6% H₂O₂ technical sheet hosted on SOSCleanroom.com. View | View PDF
- SOSCleanroom product/category guidance used for tool and chemistry examples: wipers, swabs, sterile ethanol, sterile nitrile gloves. Wipers | Swabs | Sterile ethanol | Sterile nitrile gloves