14.1 Standard Precautions, PPE & Hand Hygiene

14.1 Standard Precautions, PPE & Hand Hygiene

Quick Answer: Apply Standard Precautions to every specimen and patient contact involving blood or body fluids. Use ABHR for most clean-hand decontamination; use soap and water when hands are dirty or for C. difficile/spores. Wear task-appropriate PPE, don/doff without self-contamination, follow biohazard labels, disinfect benches with correct contact time, and know that OSHA 29 CFR 1910.1030 (Bloodborne Pathogens) drives lab exposure rules.

Infection control is a core slice of Domain IV: Laboratory Operations (about 20–25% of the ASCP MLA exam under the content guideline for testing dates beginning June 1, 2026). Outline topics cluster around precautions, PPE, hand hygiene, signs/labels, disinfection, and awareness of the federal bloodborne pathogens rule. The MLA does not invent infection-control policy, but every accession, centrifuge load, aliquot, and spill cleanup assumes you apply it correctly.

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Standard Precautions vs Transmission-Based Precautions

Standard Precautions (always on)

Standard Precautions are the baseline set of practices used for all patients and specimens, regardless of known infection status. They rest on a simple principle: you cannot always know who is infectious, so treat blood, all body fluids, secretions, and excretions (except sweat), non-intact skin, and mucous membranes as potentially infectious.

Core elements relevant to the clinical laboratory:

In the lab, “every tube is infectious until proven otherwise” is the practical mindset—even when the LIS shows no infection flag.

Transmission-based precautions (add-ons)

Transmission-based precautions are additional measures used when a patient is known or suspected to have an infection spread by a specific route. They are layered on top of Standard Precautions, not instead of them.

The MLA follows facility isolation signage and SOP when drawing or delivering specimens from isolation rooms. If you are unsure whether extra PPE is required, ask before entering—do not improvise.

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Hand Hygiene: Soap/Water vs Alcohol-Based Hand Rub (ABHR)

Hand hygiene is the single most effective routine infection-control behavior. Know when to use which method.

Alcohol-based hand rub (preferred for most routine use)

When hands are not visibly soiled, ABHR (typically 60–95% alcohol) is preferred in most clinical settings because it is faster, less drying when used correctly, and highly effective against many bacteria and viruses.

Technique concepts:

1. Apply enough product to cover all surfaces of both hands.
2. Rub palms, backs of hands, between fingers, thumbs, and fingertips until dry.
3. Do not wipe off wet product or rinse with water—alcohol needs contact time while evaporating.

Soap and water (required or preferred in key situations)

Use soap and water when:

• Hands are visibly dirty or contaminated with blood/body fluids that ABHR cannot remove mechanically
• After using the restroom
• Before eating (facility policy)
• After known or suspected exposure to spore-forming organisms, especially Clostridioides difficile (C. diff)—alcohol does not reliably kill spores; mechanical washing is preferred
• When the facility SOP specifies soap/water after certain isolation contacts

Technique concepts: wet hands, apply soap, scrub all surfaces for the recommended duration (often ~20 seconds of scrubbing is taught), rinse, dry with a clean towel, and use the towel to turn off the faucet when applicable.

Exam trap table

Gloves do not replace hand hygiene. Perform hand hygiene before donning gloves when indicated and after removing gloves—micro-tears and contamination of wrists are common.

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PPE Selection for Laboratory Work

Choose PPE based on task risk, not on whether the patient “looks sick.”

Common lab PPE

Lab coats in clinical labs are typically fluid-resistant work coats dedicated to the laboratory—not street jackets worn to the cafeteria. Contaminated coats are not hung in clean break areas. Many labs prohibit wearing lab coats in public corridors; follow local policy.

Gloves:

• Use the correct size; poorly fitting gloves tear and reduce dexterity.
• Change gloves after gross contamination, between patient contacts, and when moving from dirty to clean tasks.
• Never reuse disposable gloves.
• Do not touch clean keyboards, door handles, or phones with dirty gloves—remove gloves or use designated dirty-area controls.

Face protection for splash risk: goggles or safety glasses alone may not stop a splash to the mouth; many SOPs require a face shield or mask plus eye protection when pouring body fluids or working with open tubes that may spray.

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Donning and Doffing Order (Concepts)

Exact sequences can vary slightly by facility and isolation type, but the concept is consistent: put PPE on so coverage is complete before exposure, and remove PPE so that outer dirty surfaces do not touch clean skin or mucous membranes.

Donning (typical concept order)

1. Hand hygiene
2. Gown/lab coat
3. Mask or respirator (as indicated)
4. Eye protection / face shield
5. Gloves (extend over gown wrists)

Doffing (highest self-contamination risk)

Doffing errors cause many lab and clinical exposures. Conceptual sequence often taught:

1. Remove gloves carefully (glove-in-glove technique) without snapping.
2. Remove gown/coat by rolling dirty side inward; touch only clean inner surfaces.
3. Hand hygiene (if hands contaminated during removal).
4. Remove eye protection and mask from the rear/side ties or bands—avoid touching the front.
5. Hand hygiene again.

If a face shield is heavily contaminated, remove it carefully after gloves/gown per your SOP. Never touch your face while wearing dirty gloves. If PPE is torn or saturated during a task, stop, remove safely, perform hand hygiene, and replace PPE before continuing.

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Biohazard Signs and Labels

The biohazard symbol (three interlocking circles) and fluorescent orange/red-orange labeling communicate infectious risk.

Expect biohazard identification on:

• Specimen bags and transport containers when required
• Refrigerators/freezers storing blood and body fluids
• Sharps containers and regulated medical waste bags
• Laboratory entrance doors or designated BSL work areas
• Contaminated equipment awaiting decontamination

Do not place food or drink in biohazard-labeled refrigerators. Do not remove or cover biohazard labels on active infectious storage. Secondary containers used for transport of primary specimen tubes often need the biohazard marking when the primary label is not visible—follow DOT/IATA and facility packaging rules covered in external shipment topics.

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Disinfection of Benches and Work Surfaces

Routine and event-driven cleaning protects the next worker and the next specimen.

Principles

1. Use the facility-approved disinfectant (often a diluted bleach solution at a specified ppm/ratio, or an EPA-registered hospital disinfectant validated for bloodborne pathogens).
2. Observe the manufacturer’s contact (kill) time—wiping dry immediately may not disinfect.
3. Clean gross soil first when present; heavy organic material can inactivate some disinfectants.
4. Disinfect after spills, at end of shift or per schedule, and when surfaces are visibly contaminated.
5. Include frequently touched items per policy: centrifuge exteriors, tube racks, phones, barcode scanners, and keyboards (use IT-approved methods for electronics).

Bleach notes (when policy uses sodium hypochlorite): prepare fresh dilutions as required (many labs prepare daily); never mix bleach with ammonia or acids (toxic gases); allow contact time; rinse metal surfaces if the SOP requires corrosion control.

For a spill of blood or body fluid: restrict the area, don appropriate PPE, absorb bulk fluid with absorbent materials, apply disinfectant for full contact time, dispose of waste as regulated medical waste, and document if required. Large or high-risk spills may require supervisor or safety officer involvement.

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OSHA Bloodborne Pathogens Standard (29 CFR 1910.1030) — Awareness

The MLA should recognize the purpose of OSHA’s Bloodborne Pathogens (BBP) Standard, not memorize every legal subsection.

29 CFR 1910.1030 protects workers with occupational exposure to blood and other potentially infectious materials (OPIM). Key employer obligations you will see in training:

Your role: complete training, use provided controls, report exposures immediately, and never disable safety devices “to go faster.”

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Putting It Together: Specimen-Processing Scenario

You receive a bag of unspun serum tubes. You:

1. Perform hand hygiene and don gloves (and coat already on).
2. Inspect the bag for leaks before opening; if leaking, open in a way that contains fluid and use face protection if splash is likely.
3. Process tubes without uncapping toward your face; wipe drips with disinfectant.
4. Remove gloves, hand hygiene, then touch the clean LIS keyboard—or use designated dirty/clean zoning.
5. Disinfect the bench at the end of the batch.

Skipping face protection while pouring a urine aliquot into a pour-off tube is a classic preventable splash exposure.

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