SOSCleanroom Resource
Critical Cleaning FAQs: USP <797>/<800> SOPs, Disinfection, and Audit Readiness
In a controlled environment, “clean” is an engineered state of control defined by risk, process sensitivity, and compliance scope — not by appearance. Critical cleaning and disinfection must simultaneously manage viable and nonviable contamination, chemical residues (including non-volatile residues), and electrostatic events while protecting airflow intent and operator safety. That requires more than selecting a disinfectant: it requires a closed-loop method that links substrate selection (material, edge treatment, cleanliness and traceability), chemistry specification (grade, filtration, sterility, and water quality), application technique (coverage, directionality, wet contact time, and no-spray rules in ISO-critical areas), and documentation (lot traceability, expiry controls, and deviation-ready SOPs).
This page is a one-stop, operator-ready reference designed to help teams reduce variability and increase defensibility. It consolidates core cleanroom controls, wiper and swab standardization logic, technique details, cleanroom-grade alcohol rationale and best practices, and sporicidal use in layered programs — plus SOP checklists that turn intent into consistent, shift-to-shift execution.
- Start with Core cleanroom controls to align strategy to risk and compliance scope.
- Use the Wipers & swabs selection section to standardize substrates and formats by zone.
- Apply the Alcohol and Sporicidal modules to strengthen cleaning validation, investigation defensibility, and day-to-day execution.
- Use the SOP checklists to close gaps in training, documentation, and shift-to-shift repeatability.
Core cleanroom controls that drive outcomes
Cleanroom outcomes are a function of controllable inputs and verified execution. “Core controls” include: contamination taxonomy alignment (viable/nonviable/NVR), material compatibility and shedding control, chemistry specification (IPA grade, water quality, filtration, sterility assurance where required), application physics (wetting, dwell time, wipe mechanics, airflow-aware directionality, transfer risk), and governance (qualified work instructions, lot/expiry traceability, change control). This section establishes the control framework used to build defensible cleaning and disinfection SOPs.
Cleanroom performance is ultimately a risk-management problem: you are controlling viable and nonviable contamination, chemical residues, and electrostatic events across products, processes, and people — under a defined compliance scope.
- Product risk: Sterile vs. non-sterile needs; sensitivity to endotoxins/pyrogens, particles, and ESD drives acceptance criteria.
- Process risk: Open manipulations, high-touch steps, transfers, changeovers, and maintenance intrusions define where controls must be strongest.
- People risk: Gowning, traffic, and technique consistency are often dominant contamination sources — training and standardized work are mission-critical.
- Compliance scope: Confirm whether USP <797> (sterile compounding) and USP <800> (hazardous drugs) apply; align documentation, monitoring, and response expectations accordingly.
- Airflow and filtration: Not just HEPA — qualification plus ongoing verification. Recovery and operational behaviors materially affect outcomes.
- Flow discipline: One-way personnel and material flows; minimize crossovers and eliminate rework loops that amplify exposure opportunities.
- Surface control: Cleaning and disinfection is a method, not a product. Outcomes depend on validated chemistry, correct application, and technique.
- Evidence of control: Certification, monitoring, trending, and documented response to excursions create defensible control.
Wipers & swabs selection: standardize substrates and formats by zone
Select wipers and swabs by zone so the tool matches the risk. Key inputs are: ISO class or criticality, contaminant type (particles, fibers, residues/NVR, bioburden), surface material and sensitivity, solvent compatibility, ESD needs, and sterility/traceability requirements. This section helps you standardize the substrate (polyester, knit, microfiber, foam, polyester knit swab, etc.) and the format (size, handle length, head shape) so cleaning is consistent and defensible.
Selection is driven by substrate + edge treatment + cleanliness/traceability + format (dry vs. pre-wetted; sterile vs. non-sterile). In practice, your goal is to reduce variability: fewer “special case” products, clearer zoning rules, and documented rationale tied to contamination risk.
1) Polyester wipers (knit or similar synthetics)
- Cut-edge polyester (e.g., AlphaWipe): 100% polyester, cleanroom-manufactured; positioned for spill control, cleaning, and solution application; designed to tolerate abrasive surfaces while maintaining low-linting behavior and reducing snag/abrasion that can release particles.
- Sealed-border polyester (Vectra-processed families): sealed-border construction with processing positioned to deliver low ions, low NVRs (non-volatile residues), and low particles/fibers for critical applications.
- Sealed-edge polyester (Vertex / ThermaSeal families): sealed edges to minimize edge shed; automated process controls are positioned to improve consistency. Sterile variants are gamma irradiated and validated to a 10−6 sterility assurance level on applicable lines.
2) Microfiber / microdenier wipers (scratch-sensitive surfaces and residue removal)
- Microfiber (polyester/nylon, sealed edge): soft and non-abrasive for scratch-sensitive surfaces; also useful for removing oils/fingerprints.
- Microdenier (high filament count): positioned for sensitive surfaces and residue removal (including disinfectant residue) where standard knits may underperform.
3) Nonwoven blends (cellulose/polyester “workhorse” wipes)
- Balances sorption capacity (cellulose) with strength and lower particle release (polyester) for spill control and general-purpose cleaning where the zone risk and residue requirements allow.
4) Polypropylene wipers (low extractables profile options; often paired with alcohol formats)
- Commonly offered as pre-wetted options to control solvent delivery. A representative sterile format is melt-blown polypropylene pre-wetted with 70% IPA/30% DI water filtered through 0.2 μm on applicable lines.
5) Format drives operator behavior: dry vs. pre-wetted; sterile vs. non-sterile
- Dry: flexible chemistry selection; requires controlled mixing/dispensing and training to avoid under-wetting and inconsistency.
- Pre-wetted: improves repeatability (wetness, VOC level, handling) and reduces “spray bottle variability.”
- Sterile: supports ISO-critical handling and documentation discipline; packaged for use control with lot/expiry labeling.
CleanTips® / cleanroom-standard controls
Texwipe Cleanroom Swabs are positioned as cleanroom standards with trademarked light-green/green handles (Re. No. 5,343,973), complete thermal bond construction (no adhesives), high-precision automated manufacturing for consistent tolerances, and lot coding for traceability and quality control.
- Authenticity/traceability cue: many lines use embossed “TEXWIPE” on the handle as a practical, line-side identity control in a documentation-driven program.
1) Polyester knit swabs (ultra-clean, low background)
- Cleanroom manufactured; described as low in NVRs and ions; thermally bonded to eliminate adhesive contamination; lot coded for traceability. Some product lines specify silicone-free/amide-free packaging.
2) Foam swabs (fiber-free heads; solvent handling and precision cleaning)
- Polyurethane foam heads positioned for controlled solvent use and pinpoint access; thermally bonded construction reduces adhesive-related contamination risk.
3) Microdenier swabs (fine surface work / very small areas)
- Used where surface sensitivity, tight tolerances, and low background matter; selection should be driven by geometry and residue risk.
4) ESD-safe swabs (static control use cases)
- Static-dissipative handle designs are used for electronics and ESD-sensitive tasks; offered with knit polyester or foam heads depending on soil and surface risk.
5) High-sorbency cotton and specialty swabs (purpose-built, less “universal”)
- Use where the method and the soil justify it (for example, specialty designs and pre-wetted concepts for defined tasks). Avoid “uncontrolled substitution” between swab types in validated processes.
Standardization wins: fewer SKUs, clearer zoning rules, and documented selection logic reduce shift-to-shift variability. SOSCleanroom emphasizes authorized supply, lot traceability, and documentation discipline to support investigations and audits.
Wiping and cleaning technique (high-impact details)
Wiping is a controlled method, not a motion. Outcomes depend on: correct pre-wet level, maintaining a continuous wet film for the required contact time, single-pass directionality with overlap, frequent face changes, and defined endpoints for discard. This section explains the practical details that prevent common failures: streaking and residue, particle drag, re-deposition, cross-zone carryover, and “dry wiping” that generates friction and contamination.
- Low-linting materials: Select wipers based on shedding, extractables, and surface compatibility to avoid introducing particles or residues. (Nothing is truly “lint-free.”)
- Fold discipline: Manage wipe faces intentionally to prevent re-deposit. Change faces frequently rather than spreading soil across a larger area.
- Pattern: Clean-to-dirty and top-to-bottom patterns reduce cross-contamination. Avoid circles unless your SOP defines it for a specific soil and validates it does not increase redistribution.
- Contact time: If the surface dries early, disinfection claims may not be achieved in practice. Train for “wet for full dwell time,” including re-wet rules and how to handle early drying.
- PEC/ISO-critical application note: Favor controlled wipe application versus spraying to reduce aerosols/overspray and improve repeatability in critical zones.
Cleanroom-grade alcohol: why sterile, controlled alcohol is the standard
Cleanroom-grade alcohol is used because it is a controlled input: the concentration is specified, the water quality is defined, and the product is filtered and packaged to reduce particles, residues, and microbial risk relative to commodity solvents. In regulated and ISO-critical areas, alcohol is often the baseline chemistry for routine cleaning because it evaporates quickly, supports predictable wetting, and can be supplied with sterility and traceability controls that align with validated cleaning and disinfection programs
In ISO-classified and sterile compounding environments, alcohol is not “just alcohol.” The risk is that an uncontrolled solvent and delivery method can introduce particles, residues, variability, and documentation gaps that undermine contamination control and compromise investigation defensibility.
- Fast-acting against many vegetative organisms and can leave minimal residue when properly specified and applied.
- In sterile compounding workflows, sterile 70% alcohol is commonly used as a routine disinfectant for ISO-classified surfaces, including within primary engineering controls (PECs), when applied with disciplined technique.
- Important limitation: Alcohol is not sporicidal; it does not reliably destroy bacterial spores.
- Sterility and ISO-surface fit: general-purpose alcohol is not sterile and not packaged for ISO-critical handling.
- Particles and packaging risk: consumer bottles, pump tops, and triggers can shed particles and become contamination reservoirs.
- Residue/impurity risk: denatured alcohols and lower-grade solvents may contain denaturants or impurities that can leave non-volatile residues.
- Water-quality variability: “70%” performance is only as consistent as the water used; uncontrolled water can introduce ions/residues/microbial burden.
- Documentation gaps: missing lot traceability, expiry, and quality documentation complicate investigations and change control.
- PEC rule: Do not spray in the hood. Apply alcohol using sterile, low-linting wipes/applicators to control aerosols/overspray and support consistent coverage.
- Sequence: Clean first (soil removal), then disinfect. Use alcohol as a routine step defined by the SOP — not as a substitute for cleaning when soils are present.
- Drying: Allow surfaces to fully dry before initiating or resuming activities to support intended effectiveness and reduce recontamination through wet contact/pooling.
Sporicidal disinfectants: specific uses, where they fit, and when they are needed
Use a sporicide when spore risk matters or when routine disinfectants are not sufficient. Common triggers include: aseptic/ISO-critical areas, adverse environmental monitoring (EM) trends, post-incident response, periodic rotation requirements, and risk assessments tied to product/process sensitivity. This section clarifies where sporicides belong (routine rotation vs. targeted event-driven use), what must be controlled (coverage, wet contact time, neutralization/residue control), and what to watch for (material compatibility and operator safety).
If a contamination-control program relies only on non-sporicidal disinfectants, bacterial spores and other highly resistant environmental forms can persist on surfaces, seed recurring contamination, and drive long-cycle “resident flora” problems that routine chemistries may not reliably eliminate.
- Designed to inactivate bacterial spores and other resistant forms that can survive routine disinfection.
- Spores can persist in seams, corners, and residue-prone areas and repeatedly reintroduce contamination if the program never includes a sporicidal “reset.”
- Clean: Remove soils/residues so chemistry contacts the surface.
- Routine disinfect: Daily/shift control for vegetative organisms.
- Sterile alcohol (as applicable): Fast, routine surface disinfection for ISO/PEC workflows; not sporicidal.
- Periodic + event-driven sporicide: Reduces spore burden and provides a deliberate reset mechanism.
- Routine cadence: Define a minimum schedule for classified areas — commonly monthly or risk-based by zone (higher-risk zones more frequent).
- After viable excursions: adverse trends, repeated mold recoveries, recurring Bacillus, or “resident flora” signals.
- After disruptive events: maintenance intrusions, construction, HVAC upset, water leaks, drain backups, ceiling disturbance, power outages.
- After procedural breakdowns: gowning breaches, uncontrolled traffic, improper material introduction, spill events beyond the initial footprint.
- PEC / ISO-critical interiors: work surface, side/back walls, sash/door interfaces, high-touch interior surfaces (per SOP and compatibility limits).
- ISO rooms and support areas: pass-through interiors, carts, handles, staging shelves, counters, floors near entry points.
- Interfaces and pockets: seams, corners, underside edges, gaskets — typical accumulation points for residues and resident contamination.
- Pre-clean first: sporicides do not reliably cut through heavy films.
- Control wet contact time: “wet for full dwell time” must be explicit, including re-wet rules.
- Prefer wipe application in critical zones: reduces aerosolization and improves repeatability.
- Residue management: many sporicides leave films; define when a follow-up wipe with sterile water and/or sterile alcohol is required.
- Compatibility and safety: define do-not-use surfaces, PPE, ventilation notes, and spill response to prevent corrosion/operator exposure.
Standard and advanced documented SOPs (compounding pharmacies)
SOPs in compounding pharmacies are not paperwork; they are risk controls and the primary evidence base during inspections. USP <797> establishes expectations spanning personnel practices and training, facilities and environmental controls, environmental monitoring, and storage/testing requirements. Standard SOPs define routine work (cleaning and disinfection steps, frequencies, contact times, material staging, garbing, aseptic manipulations, and required logs). Advanced SOPs govern “when things change or go wrong” (investigations, EM excursions, corrective actions, product hold/release, requalification triggers, and change control), including HD-specific workflows when USP <800> applies.
SOPs are where cleanroom intent becomes cleanroom reality. Strong programs treat SOPs as controlled documents with training linkage, periodic requalification, and evidence-based updates after deviations.
Standard SOP set (baseline control)
- Personnel flow and gowning: entry sequence, hand hygiene, glove disinfection cadence, and “no-touch” rules for critical surfaces.
- Material flow: staging, wipe-down, pass-through rules, carton removal, and disinfection steps by zone.
- PEC cleaning/disinfection: defined sequence, products, dwell time, wipe type, and documentation (including “no spray” rule in ISO-critical areas).
- Room cleaning/disinfection: daily/shift tasks, weekly tasks, floors/walls/doors, high-touch surfaces, and zone-based frequency.
- Environmental monitoring response: alert/action levels, investigation workflow, CAPA, and requalification triggers.
- Waste handling: routine waste, sharps, and segregation rules by risk.
Advanced SOP set (audit-ready, deviation-resilient)
- Sporicidal rotation & event-driven reset: cadence by zone, trigger criteria, residue-management step, compatibility controls.
- Hazardous drug (USP <800>) surface sequence: deactivation/decontamination → cleaning → disinfection (with defined chemistries and PPE).
- Disinfectant preparation controls: mixing (if applicable), filtration, sterile transfer, labeling, expiry, and “no-top-off” rules.
- Wiper/swab standardization matrix: approved substrates by zone, with change control and validation notes for substitutions.
- Excursion playbooks: mold recovery, repeated Bacillus, trend drift, HVAC upset, water leak, maintenance intrusion (each with predefined containment and recovery steps).
- Training and proficiency: initial qualification, annual competencies, direct observation checklists, and corrective coaching triggers.
Source basis
- Texwipe — Cleanroom Wipes overview (sealed-border / sealed-edge vs. cut-edge families; contamination metrics testing emphasis).
- Texwipe — AlphaWipe product page (100% polyester cut-edge; spill control/cleaning/solution application positioning).
- Texwipe — Vectra Alpha 10 product page (sealed-border; Vectra processing; low ions/NVR/particles/fibers positioning).
- Texwipe — Vertex sterile wipers product pages + Sterile Products overview (gamma irradiation; 10−6 SAL language; lot/expiry documentation positioning).
- Texwipe — PolySat sterile pre-wetted wipers (melt-blown polypropylene; 0.2 μm filtered USP-grade 70% IPA / 30% DI water positioning on applicable lines).
- Texwipe — Alpha 1 Microfiber wipers (80/20 polyester/nylon microfiber; sealed edge; scratch-sensitive surfaces positioning).
- Texwipe — Swabs overview + Alpha swab pages + representative foam swab pages (thermal bond/no adhesive, traceability, trademarked handle language, and positioning by substrate family).
- SOSCleanroom — Wipers category overview (portfolio framing: dry vs. pre-wetted; sterile vs. non-sterile; application-driven selection).
- SOSCleanroom — Representative Texwipe datasheets hosted on SOSCleanroom (example: PolySat and nonwoven blend datasheets reflecting substrate/solution/sterility documentation conventions).
- Texwipe “Critical Cleaning for Life Sciences” brochure hosted on SOSCleanroom (portfolio framing across wipers/sterile products/swabs for life sciences; handling/validation support themes).
- CDC (Infection Control: Chemical Disinfectants) — alcohol activity profile and limitations, including non-sporicidal limitation.
- USP public overview page for General Chapter <797> (scope: personnel, facilities, environmental monitoring, etc.).
- Selected institutional/clinical training references summarizing USP <797> surface disinfection practices in PECs (wipe application emphasis; “no spray” in hood training convention).