Biohazard Safety Precautions in Forensic Science

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Biohazard Safety Precautions in Forensic Science
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Universal Precautions

• As defined by OSHA(Occupational Safety and Health
  Act)
• All blood and certain body fluids are considered
  potentially infectious for Hepatitis B
  virus(HBV), Hepatitis C virus(HBC), Human
  immunodeficiency virus(HIV), and other bloodborne
  pathogens

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What is a Blood-Borne Pathogen?

• Pathogenic organisms that present in human blood,
  human blood components, and products made from
  human blood that can cause disease in humans.

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Body Fluids that require application of universal
Precautions

• Blood
• Semen
• Vaginal fluid
• Tissue(unfixed)
• Synovial fluid(around joints)
• Amniotic Fluid(around the baby)

• Peritoneal fluid(in abdomen)
• Spinal fluid
• Pleural fluid(lungs)
• Pericardial fluid ( heart)
• Any body fluid that is visibly bloody

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It is not known about the blood at a crime scene
or on items of evidence therefore, it is policy
to follow universal precautions at all times.
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HIV

• HIV is a retrovirus associated with Acquired
  Immunodeficiency Syndrome(AIDS)

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BODY fluids that can transmit HIV

• Blood
• Semen
• Vaginal secretions
• And possibly breast milk
• HIV has been isolated also from saliva, tears,
  urine, cerebrospinal fluid, amniotic fluid, and
  tissues of infected person but can be transmitted
  to another person through these fluids

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Survivability of HIV

• CONDITION SURVIVABILITY
• Liquid at room temperature 15 days(minimum)
• Refrigerated liquid Much longer than 15 days
• Dried form at room temp. 3 to 13 days
• Dried form frozen much longer than 13 days

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Hepatitis

• Infection or inflammation of the liver

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5 Types of Hepatitis

• HAV(Hep A)-contracted through fecal and oral
  routes.
• HBV(Hep B)-contracted through nonintact skin or
  puncture such as needle sticks. Most common
  laboratory-associated infection
• HCV(Hep C)-contracted through nonintact skin and
  punctures such as needle sticks. It has been
  detected primarily in blood and serum, less
  frequently in saliva, and rarely in urine or
  semen.
• HDV(Hep D)-a defective virus and requires the
  presence of hepatitis B for replication
• NonA, NonB, NonC, hepatitis-collective name for
  all other hepatitis viruses contracted via non
  intact skin

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5 Types of Hepatitis

• 4. HDV(Hep D)-a defective virus and requires the
  presence of hepatitis B for replication
• 5. NonA, NonB, NonC, hepatitis-collective name
  for all other hepatitis viruses contracted via
  non intact skin

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• A human host is 100 times more likely to contract
  hepatitis than HIV .
• Although HIV has received more attention, the
  risk of contracting HBV is actually much greater.

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Contact Routes of Exposure

• Direct oral route via blood or other body fluids
  entering the mouth.
• Indirect oral route via smoking or placing
  pencils in mouth.
• Ocular route via splashing infectious material
  into the eyes or rubbing the eyes
• Inoculation route via puncture wounds caused by
  needles or other sharp objects
• Respiratory route via direct respiratory contact
  or aerosal production.

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• Hands should be washed with warm water and a
  germicidal soap immediately following contact
  with infectious materials and after completion of
  all procedures , including the removal of
  protective gloves.

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Minimizing Contamination at the Crime Scene

• ESTABLISH A CLEAN AREA
• Leave all supplies and equipment in the clean
  area until needed.
• Organize and assemble equipment .. Take only
  necessary equipment and supplies into the scene
  since anything that enters the scene becomes
  potentially contaminated.
• Determine the type of PPE(protective personal
  equipment) needed.

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• Each scene should be assessed initially by
  questioning knowledgeable individuals who have
  already arrived and performed and evaluation
  walk-through.

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Guidelines for Selecting PPE

• Wear protective gloves as a minimum precaution.
• Wear face mask or eye shields if the potential
  for fluid splash exists or aerosolization is
  present.
• Wear protective suit and shoe coverings if
  clothing contamination is possivle.

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Guidelines for Selecting PPE cont.

• Replace gloves and other PPE items when visibly
  soiled, deteriorated, or torn.
• Discard surgical or examination gloves. Do not
  wash or disinfect them for reuse.
• Remove gloves and other PPE before leaving the
  work area.

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Guidelines for Selecting PPE cont.

• Use gloves if you have cuts or dermatitis.
• Set up a discard location for disposal of
  contaminated PPE and supplies when the scene is
  exited.
• Secure disposal bags to prevent accidental spills.

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Guidelines for Selecting PPE cont.

• Prepare bleach or other decontamination solution
  fresh each day. It should be diluted 110 with
  water(approximately 1/2 cup of bleach in a quart
  of water). A minimum of 10 minutes contact time
  is necessary.

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Precautions for Evidence Collection

• Be aware of syringes, needles, knives,razors,nails
  , broken glass, or sharp metals nearby.
• Do not reach into confined or blind spaces before
  checking them with a flashlight or mirror.
• Use caution when collecting biological specimens
  to avoid contamination.

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Precautions cont.

• Change gloves between each item of evidence
  collected to prevent cross-contamination.
• Use masks and eye protection to avoid aerosol
  exposure when scraping or cutting dried stains.
• Use caution with knives and scissors to avoid
  surface cuts and contamination from body fluids
  when cutting out stains

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Precautions cont.

• Use a syringe to collect a wet stain. Do not use
  a needle on a syringe unless absolutely necessary
  since a needle will make the opening smaller and
  collection will be more difficult. Needles also
  present sharp hazards.

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Packaging Evidence

• Package each item separately to prevent
  cross-contamination.
• Use puncture-resistant containers when packaging
  sharp pieces of evidence. Write sharp on the
  outside of each container..

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Packaging Evidence

• Package wet items in plastic only when necessary.
• Keep evidence in plastic only as long as needed
  for transport.
• Air dry at room temp ASAP. Do not use direct
  sunlight or a hair dryer to speed drying time.
• Repackage dried evidence in a paper container.

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Packaging Evidence cont.

• Use tape when closing a container. Write your
  initials across the tape to ensure integrity of
  the package.
• Do not use staples. They create sharp hazards.
  It is also difficult to ensure the integrity of a
  package that has been fastened with staples

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Packaging Evidence cont.

• Ensure that appropriate labeled containers are
  prepared for the disposal of contaminated items.
• Follow all steps of the established procedure at
  the discard station.

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Discard Station Procedure

• Items should be handled in sequential order.
• Disposable equipment and supplies
• Non disposable equipment and supplies
• PPE

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Discard Station Procedure

• Disposable equipment and supplies should be
  classified if they represent sharp hazards.
• Non sharp disposables such as paper scales, film
  boxes, and film canisters may be discarded
  directly into collection containers.

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Discard Station Procedure

• Sharp disposables such as scalpels, pens, or
  pencils, and broken glassware, should be first
  packaged in cardboard, plastic, or another type
  of rigid container,and discarded into a
  collection container to prevent punctures.

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Discard Station Procedure

• Non Disposable equipment and supplies such as ink
  pens to be reused, markers, crime scene kits,
  camera, safety glasses, reusable rulers, and
  scales should be decontaminated with diluted
  bleach or commercial wipes and returned to their
  proper storage areas. Cleaning supplies should
  be discarded into a collection container.

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Removal of PPE to Minimize Exposure

• Remove eye covers and decontaminate them if
  reusable. Return them to their proper storage
  location. Place cleaning supplies and disposable
  PPE items in a discard container.
• Remove masks and head coverings with caution to
  prevent indirect exposure and place them in a
  discard container.

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Removal of PPE to Minimize Exposure

• Remove shoe covers via a roll-off techniques.
  Invert the uncontaminated interior over the
  contaminated outer surface and pull the cover off
  . Place it in a discard container.
• Roll off the protective suit. Invert the
  uncontamined interior over the contaminated
  surface and pull the suit off. Place it in a
  discard container.

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Removal of PPE to Minimize Exposure

• Remove gloves last. Start at the wrist and peel
  the glove off one hand. Grasp the removed glove
  in the still gloved hand. Roll down the top of
  the remaining glove. Grasp the uncontaminated
  inner surface of the glove and peel it off while
  tucking the first glove inside the second glove.
  Place the glove in a discard container.

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Removal of PPE to Minimize Exposure

• Close the discard container by grasping the bag
  beneath the rolled-down top. Pull the top of the
  bag upward to close it. Secure the tops of bags
  with tape or twist ties to prevent spills.
• Wash hands with warm water and germicidal soap.
  Vionex, Cal-stat or Sani-cloth maybe used if no
  handwashing facility available. Wiping is
  temporary alternative. It is not a substitute.

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• The removal and disposal of contaminated
  materials, supplies, testing items, and PPE are
  responsibilities of the agency at a crime scene.