3.2 Decontamination Environment, Airflow & Personal Protective Equipment (PPE)

3.2 Decontamination Environment, Airflow & Personal Protective Equipment (PPE)

The decontamination area of the Central Service / Sterile Processing Department (SPD) serves as the primary physical barrier between contaminated medical devices arriving from patient care areas and the clean assembly/sterilization zones. Because this area receives heavily soiled, bioburden-laden instruments, its physical environment, ventilation systems, and personal safety controls are strictly regulated. Standards established by ANSI/AAMI ST79, ASHRAE Standard 170, and OSHA govern the parameters of the decontamination space to protect technicians from bloodborne pathogens and aerosolized infectious agents, control microbial proliferation, and prevent cross-contamination into adjacent clean processing areas.

Environmental Parameters and Control Standards

Maintaining precise environmental conditions within decontamination is essential. Fluctuations in room temperature, relative humidity, or air exchange rates directly impact worker health, microbial growth rates, and airborne contaminant containment.

Air Pressure and Directional Airflow

The decontamination room must maintain negative air pressure relative to all surrounding corridors, clean assembly areas, and storage rooms.

• Mechanism: Negative pressure is achieved by continuously exhausting more air out of the room than is supplied into it.
• Directional Flow: When doors to the decontamination area are opened, air naturally flows inward from clean corridors into the dirty room. This prevents airborne microorganisms, bioaerosols generated during manual scrubbing, and unpleasant odors from escaping into clean facility zones.
• Verification: Air pressure differentials must be monitored continuously with physical pressure gauges or daily using a visual tissue/smoke test at entry doors.

Air Exchange Rates and Exhaust

Proper ventilation dilutes airborne contaminants and removes bioaerosols. Decontamination rooms must maintain a minimum of 10 total air exchanges per hour (ACH). Furthermore, ventilation systems must be designed so that 100% of the room air is exhausted directly to the outside of the building. Air from decontamination must never be recirculated into other areas of the hospital unless passed through certified High-Efficiency Particulate Air (HEPA) filtration systems.

Temperature and Relative Humidity

Environmental temperature and humidity ranges in decontamination are tightly controlled to balance technician safety with infection control principles:

• Temperature Range: 60°F to 65°F (16°C to 18°C). Because technicians in decontamination must wear heavy, fluid-impermeable Personal Protective Equipment (PPE), higher ambient temperatures cause severe physical fatigue, heat stress, and excessive sweating. Sweat dripping onto instruments compromises clean surfaces, and higher temperatures accelerate microbial multiplication in standing water.
• Relative Humidity (RH) Range: 30% to 60%. Humidity below 30% causes environmental dust to remain suspended in air currents, carrying desiccated microbes across work surfaces. Humidity above 60% fosters fungal and mold growth, causes condensation on cool stainless steel surfaces, and weakens paper-based packaging materials stored in adjacent spaces.

Personal Protective Equipment (PPE) Requirements

Working in the decontamination room exposes technicians to blood, bodily fluids, hazardous cleaning chemicals, sharp surgical instruments, and bioaerosols generated during scrubbing and ultrasonic cleaning. OSHA’s Bloodborne Pathogens Standard (29 CFR 1910.1030) mandates that healthcare facilities provide appropriate PPE at no cost to employees and enforce its proper use.

Required PPE Components

Standard attire (hospital scrubs) is not PPE. Before entering the active decontamination processing area, technicians must don a complete barrier ensemble consisting of:

1. Fluid-Resistant Gown or Apron: Must be constructed of fluid-impermeable or fluid-resistant material with long sleeves and snug cuffs. It must provide full coverage from the neck to below the knees and wrap around the back to prevent blood or chemical soak-through.
2. Heavy-Duty Utility Gloves: Thin latex or nitrile examination gloves are prohibited for manual cleaning in decontamination. Technicians must wear heavy-duty, puncture-resistant, fluid-resistant utility gloves made of nitrile, neoprene, or butyl rubber with extended cuffs extending well up the forearm over gown sleeves. Utility gloves protect against chemical burns, puncture injuries from sharp instruments, and fluid penetration.
3. Facial Protection: To guard against splashing fluids, blood droplets, and cleaning chemicals, facial protection is mandatory. Technicians must wear either a full-face shield that wraps around the face and extends below the chin, OR a fluid-resistant surgical mask combined with protective goggles/eyewear featuring solid side shields. Note: Standard prescription eyeglasses do NOT qualify as eye protection.
4. Fluid-Resistant Shoe Covers / Footwear: Technicians must wear fluid-impermeable shoe covers that cover the entire shoe or dedicated waterproof rubber work boots with non-skid soles to protect feet from falling sharps and standing liquid spills.

Donning and Doffing Sequences

The order in which PPE is donned (put on) and doffed (removed) is critical to prevent self-contamination and the spread of pathogens across facility boundaries.

Donning (Putting On) Sequence

Donning should occur in a clean anteroom or dedicated donning area prior to entering the active decontamination work zone:

1. Shoe Covers: Slip fluid-resistant covers over work shoes.
2. Fluid-Resistant Gown: Put on gown, insert arms into sleeves, and fasten secure ties at the neck and waist.
3. Surgical Mask / Respirator: Secure ties or ear loops over ears and pinch nosepiece to fit snugly over nose bridge and chin.
4. Goggles or Face Shield: Place over eyes/face and adjust headband for a snug fit.
5. Heavy-Duty Utility Gloves: Pull utility gloves over hands, extending cuffs securely over the wrist cuffs of the fluid-resistant gown.

Doffing (Taking Off) Sequence

Doffing must take place at the designated exit area of decontamination before stepping into clean corridors. The outer surfaces of PPE are considered heavily contaminated:

1. Utility Gloves: Remove gloves using a glove-to-glove, skin-to-skin technique to avoid touching contaminated outer glove surfaces with bare hands.
2. Hand Hygiene: Perform immediate hand hygiene using an alcohol-based hand rub or soap and water (crucial step after glove removal).
3. Face Shield or Goggles: Remove from the back of the head/headband without touching the front contaminated shield surface.
4. Fluid-Resistant Gown: Unfasten ties, peel gown away from shoulders and neck down inside-out, folding contaminated outer surfaces inward into a bundle, and discard.
5. Mask: Unhook ear loops or untie bottom then top ties and discard without touching the front filter mask surface.
6. Shoe Covers: Remove shoe covers from the heel forward and discard.
7. Final Hand Hygiene: Wash hands thoroughly with antimicrobial soap and water for a minimum of 20 seconds.

Strict adherence to these environmental boundaries and PPE protocols creates an effective barrier against occupational exposure and environmental contamination.