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Hematology

Safety

The Hematology laboratory presents a unique environment where biological hazards (fresh whole blood) and chemical hazards (stains and fixatives) intersect. Safety operations are strictly governed by the Occupational Safety and Health Administration (OSHA) and Department of Transportation (DOT) to protect laboratory personnel, couriers, and the public. A comprehensive safety program relies on a hierarchy of controls, ranging from engineering devices to personal behavior

Safety Programs & Practices

The foundation of laboratory safety is the OSHA Bloodborne Pathogens Standard, which mandates the use of Standard Precautions. This concept dictates that all human blood, body fluids, and tissues are treated as if they are known to be infectious for HIV, Hepatitis B (HBV), and Hepatitis C (HCV), regardless of the patient’s actual diagnosis. There are no exceptions for “low-risk” populations

Prevention of Infection & PPE

  • Engineering Controls: These isolate the hazard from the worker. Examples include safety-engineered needles (retractable or shielding), sharps containers (puncture-resistant, leak-proof), and biosafety cabinets (used for processing body fluids or making bone marrow slides to contain aerosols)
  • Hepatitis B Vaccination: Employers must offer the Hepatitis B vaccine series to all potentially exposed employees at no cost within 10 days of initial assignment. Employees who decline must sign a mandatory declination form
  • Personal Protective Equipment (PPE)
    • Gloves: Nitrile is preferred over latex for chemical resistance. They must be changed between every patient and immediately if torn
    • Lab Coats: Must be fluid-resistant with knit cuffs (to prevent sleeves from dragging in stains/specimens) and fully buttoned
    • Face Protection: Shields or masks with goggles are required during procedures that generate splashes, such as manually uncapping tubes or making wedge smears

Safe Work Practices

  • Hand Hygiene: The most effective infection control measure. Hands must be washed with soap and water immediately after removing gloves. Alcohol-based rubs are insufficient if hands are visibly soiled with blood or biological material
  • Aerosol Prevention: When manually uncapping a vacuum tube, the stopper should be covered with gauze and twisted gently away from the face to catch the “pop” (aerosol release). Centrifuges must be capped or have sealed buckets; if a tube breaks, the unit must be left closed for 30 minutes to allow aerosols to settle
  • Prohibited Acts: Eating, drinking, smoking, applying cosmetics, and handling contact lenses are strictly prohibited in technical work areas. Mouth pipetting is never permitted

Safety Data Sheets (SDS)

Under the OSHA Hazard Communication Standard (“Right to Know”), laboratories must maintain a GHS-formatted, 16-section SDS for every chemical. Staff must review these to understand specific hazards

  • Wright-Giemsa Stain: Contains Methanol, which is highly flammable and toxic (causes blindness/death if ingested). Use in well-ventilated areas
  • Lysing Agents: Often contain Sodium Azide as a preservative. Azide creates acutely toxic gas if mixed with acid and can form explosive salts if allowed to react with copper or lead plumbing (flush drains copiously)
  • Drabkin’s Reagent: Contains Cyanide. Fatal if swallowed. Requires specific hazardous waste disposal

Emergency Procedures

Rapid response to accidents minimizes injury and exposure. All staff must be trained on the location of safety showers, eyewash stations, and fire extinguishers

Biohazard Exposures

  • Percutaneous Injury (Needlestick)
    1. Wash: the wound immediately with soap and water (do not squeeze or bleach)
    2. Report: the incident to a supervisor immediately
    3. Evaluate: the source patient (test for HIV/HBV/HCV if consent is obtained) and the employee (baseline testing). Post-Exposure Prophylaxis (PEP) may be initiated based on risk
  • Mucous Membrane Splash
    • Eyes: Flush at an eyewash station for a minimum of 15 minutes, holding the eyelids open
    • Mouth/Nose: Rinse thoroughly with water (do not swallow)

Fire Safety

  • RACE: Rescue anyone in danger, Alarm (pull the alarm/call 911), Contain (close doors), Extinguish or Evacuate
  • PASS: When using an extinguisher: Pull the pin, Aim at the base of the fire, Squeeze the handle, Sweep side to side

Packaging & Transportation of Specimens

Transporting biological specimens is regulated by the DOT (ground) and IATA (air). Improper packaging can lead to leaks, fines, and public health risks. Most hematology diagnostic samples are classified as Category B Biological Substances (UN 3373)

The Triple Packaging System

  • Primary Receptacle: The tube holding the blood. It must be leak-proof and wrapped in absorbent material capable of absorbing the entire liquid content if the tube breaks
  • Secondary Packaging: A leak-proof container (e.g., a sealed biohazard bag or canister) that encloses the primary receptacle and absorbent material
  • Outer Packaging: A rigid container (fiberboard box) capable of withstanding physical shock (drop test). It must display the UN 3373 diamond label and the text “Biological Substance, Category B”

Dry Ice & Internal Transport

  • Dry Ice (UN 1845): Used for shipping frozen plasma. It is a Class 9 hazard. The package must be vented (not airtight) to allow Carbon Dioxide gas to escape, preventing explosion. The net weight of the dry ice must be listed on the label
  • Pneumatic Tube Systems: Used for internal hospital transport. Carriers must be padded to prevent tube breakage. System acceleration/deceleration can cause hemolysis (elevating Potassium and LDH, lowering RBC count), so sensitive samples should be hand-delivered