Pub Health 4310 Health Hazards in Industry

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Pub Health 4310Health Hazards in Industry

• David Wallace
• Lecture 7
• Biohazards in the Work Environment

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Biohazards in the Work Environment

• Objectives
• Appreciate the how the industrial hygiene
  approach to biological agents is different
• Understand the "chain of infection"
• Be familiar with guidelines for bloodborne
  pathogens and tuberculosis 
• Know about biosafety basics
• The 4 biosafety Levels
• Appropriate controls for biosafety levels
• Biosafety cabinets
• Biosafety in laboratories

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Biohazards in the Work Environment

• Based on
• Chapter 18 of The Occupational Environment, its
  Evaluation and Control
• CDC Guidelines for Tuberculosis and Blood-borne
  Pathogens
• CDC biosafety levels
• OSHA

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Biohazards in the Work Environment

• Introduction
• Increased awareness of biological agents
• Newly identified diseases
• Recombinant DNA
• Concern among general public and occupational
  hygienists
• Biohazards are common in certain industries
• Agriculture
• Healthcare
• Biotechnology
• Research and clinical labs

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Biohazards in the Work Environment

• Introduction
• Biological agents are inherently different from
  chemical and physical agents
• IH principles of anticipation, recognition,
  evaluation and control apply
• Air sampling typically is not done
• Biological samples are often collected
• Wipe samples from workers
• PPE (primary barrier protection) is important
• Inhalation and skin contact are important routes
  of transmission

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Biohazards in the Work Environment

• Biological Risk Assessment
• Risk assessment goals
• Predict probability of a given outcome
• Identify and recommend control strategies
• Special concerns for biological materials
• No threshold of exposure
• Ubiquitous in the environment
• Affected by biological competition

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Biohazards in the Work Environment

• Host, Agent and Environment
• 6 conditions for infection and illness
• pathogenic agent
• Reservoir for organism
• Escape from reservoir
• Move through environment
• Portal of entry (broken skin, inhalation, etc.)
• Susceptible host
• Interrupting any one of these conditions stops
  the disease

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Biohazards in the Work Environment

• Risk Assessment Process
• Identify agents, gather data
• Evaluate effluent streams where biohazards can
  escape containment
• Determine level of PPE and lab practices
• Determine availability of PPE and equipment
• Assess facility to contain material during normal
  and emergency situations
• Determine whether potential exposure is
  permissible
• Ethics, policy, law
• Notify local officials about planned use and
  precautions
• Consider whether acceptance of risk is voluntary
• Recognize factors which give illusion of lack of
  risk

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Biohazards in the Work Environment
Working Safely with Biological Agents

• Bloodborne Pathogens
• CDC
• OSHA
• Tuberculosis
• Biosafety

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Biohazards in the Work Environment
Working Safely with Biological Agents

• Bloodborne Pathogens
• CDC Guidelines
• Guidelines for Prevention of Transmission of
  Human Immunodeficiency Virus and Hepatitis B
  Virus to Health-Care and Public-Safety Workers,
  1989
• http//aepo-xdv-www.epo.cdc.gov/wonder/prevguid/p0
  000114/p0000114.asp
• Biohazard Signage and Labeling

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Working Safely with Biological Agents

• Bloodborne Pathogens
• OSHA Bloodborne Pathogens Standard
• 1991 standard, 29 CFR 1910.1030
• Applies to all occupational exposure to blood or
  Other Potentially Infectious Material (OPIM)
• Exposure Control Plan
• Universal precautions
• Engineering and work practice controls
• Hand washing
• Sharps handling
• 2000 law requires OSHA to emphasize sharp
  technology
• Engineered Sharps Injury Protections

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Biohazards in the Work Environment

• Working Safely with Biological Agents
• Bloodborne Pathogens
• OSHA Bloodborne Pathogen Standard
• Injury log
• Eating, smoking, applying cosmetics prohibited
• Procedures for blood or OPIM
• Personal Protective Equipment (PPE)
• Gloves
• Eye protection
• Gowns

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Biohazards in the Work Environment

• Working Safely with Biological Agents
• Bloodborne Pathogens
• Bloodborne Pathogen Standard
• Housekeeping
• Waste
• Requirements for HIV and HBV Research
  Laboratories and Production Facilities.
• Standard Microbiological Practices
• Special Practices
• Containment Equipment.
• Hepatitis B Vaccination and Post-exposure
  Evaluation and Follow-up
• Medical Recordkeeping
• Communication of Hazards to Employees
• Information and Training

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Biohazards in the Work Environment

• Working Safely with Biological Agents
• Tuberculosis
• CDC guidelines for healthcare facilities,
  http//www.cdc.gov/nchstp/tb/pubs/mmwr/rr4313.pdf
  
• TB Infection-control plan
• Identifying suspect TB patients
• Managing patients who may have active TB
• Engineering controls
• General ventilation
• Additional controls (HEPA filtration, Germicidal
  Ultraviolet radiation)
• Respiratory protection
• Cough-inducing procedures
• Education and training
• Healthcare worker counseling, screening, and
  evaluation

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Biohazards in the Work Environment

• Working Safely with Biological Agents
• Tuberculosis
• OSHA enforcement
• 1997 Proposed TB standard, withdrawn in 2003
• 1996 Compliance directive,
• http//www.osha.gov/pls/oshaweb/owadisp.show_docum
  ent?p_tableDIRECTIVESp_id1586
• Citations under the General Duty Clause, 5(a)(1)

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Biohazards in the Work Environment

• Biosafety
• Biosafety Cabinets
• Class I to III
• Biosafety levels
• Levels 1-4
• Based on risk
• Biosafety guidelines

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Biohazards in the Work Environment

• Biosafety Cabinets

Class III cabinet, for high risk agents
Class II, for moderate risk agents
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Biosafety Cabinets
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Biohazards in the Work Environment

• Biosafety Levels
• National Institutes of Health
• 4 levels, based on risk
• BSL1 Not known to cause disease
• Bacillus subtilis
• BSL2 Known to cause disease, therapeutic
  intervention available
• Salmonella, Legionella, Giardia
• BSL3 Serious lethal risk, high individual risk
• HIV, yellow fever, rabies
• BSL4 Life threatening, no therapeutic control
• Ebola, Marburg, etc.
• Only a few BSL4 facilities, usually military or
  govt.

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Biohazards in the Work Environment

• Biosafety Guidelines
• General Guidelines for laboratories
• Lab Practices and Techniques
• Knowledgeable supervisor and personnel
• Aware of potential hazards
• Proficient in practices/techniques
• Biosafety manual specific to lab
• Safety Equipment
• Primary Barriers
• Biosafety cabinets (BSCs) BSL-2/3
• Personal protective clothing
• Pipetting Devices
• Safety centrifuge cups and rotors
• Eye and face protection
• Respiratory protection BSL-3

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Biohazards in the Work Environment

• Biosafety Guidelines
• Principles of Biosafety
• Biosafety Levels 1-3 Guidelines to describe
  combinations of
• Laboratory Practices and Techniques
• Standard Practices
• Special Practices
• Safety Equipment (Primary Barriers)
• Laboratory Facilities (Secondary Barriers)
• Increasing levels of personnel and environmental
  protection

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Biohazards in the Work Environment

• Biosafety Guidelines
• Biosafety Level 1
• For well-characterized agents not known to cause
  disease in healthy adult humans, minimal
  potential hazard to laboratory personnel and the
  environment.
• Examples bacillus subtilis naegleria gruberi
  infectious canine hepatitis virus E. coli
• Facility design
• Easily cleaned and decontaminated
• Sink for hand washing
• Work surfaces easily cleaned
• Bench tops
• Sturdy furniture
• Windows fitted with fly screens

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Biohazards in the Work Environment

• Biosafety Guidelines
• Biosafety Level 1
• Work practices
• Use mechanical pipetting devices
• Wash hands
• Restrict or limit access when working
• Prohibit eating, drinking and smoking

• Minimize splashes and aerosols
• Decontaminate work surfaces daily
• Decontaminate wastes
• Maintain insect rodent control program

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Biohazards in the Work Environment

• Biosafety Guidelines
• Biosafety Level 1 (cont.)
• Protective clothing
• Lab coat
• Gloves
• Additional PPE may be needed
• Face protection
• Eye protection
• Personnel
• Supervision
• scientist with general training in Microbiology
  or related science
• Lab Personnel
• Specific training in lab procedures

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Biohazards in the Work Environment

• Biosafety Guidelines
• Biosafety Level 2
• Suitable for work involving agents of moderate
  potential hazard to personnel and the environment
  
• Immunization or antibiotic treatment is available
  
• Examples
• Measles virus
• Salmonellae
• Toxoplasma spp.
• Hepatitis B virus

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Biohazards in the Work Environment

• Biosafety Guidelines
• Biosafety Level 2 (cont.)
• Work Practices as in BSL-1, with emphasis on
• Gloves
• Mechanical pipetting
• Attention to sharps
• Needles Sharps Precautions
• DONT break, bend, re-sheath or reuse syringes or
  needles
• DO use sharps containers
• DONT touch broken glass with hands
• DO use plastic-ware

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Biohazards in the Work Environment

• Biosafety Guidelines
• Biosafety Level 2
• Policies and procedures for entry
• Biohazard warning signs
• Biosafety manual specific to lab
• Training with annual updates
• Immunizations
• Baseline serum samples
• Decontaminate work surfaces
• Report spills and accidents
• No animals in laboratories
• Use biosafety cabinets (class II) for work with
  infectious agents involving
• Aerosols and splashes, large volumes or high
  concentrations

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Biohazards in the Work Environment

• Biosafety Guidelines
• Biosafety Level 2 (cont.)
• Facility Design for BSL-1 Facilities PLUS
• Autoclave available
• Eyewash station available
• Personnel
• Supervision
• Supervisor is a competent scientist with
  increased responsibilities
• Limits access if immunocompromised
• Restricts access to immunized
• Lab Personnel
• Aware of potential hazards
• Proficient in practices/techniques

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Biohazards in the Work Environment

• Biosafety Guidelines
• Biosafety Level 3
• Suitable for work with infectious agents which
  may cause serious or potentially lethal disease
  as a result of exposure by the inhalation route.
• Exposure potential to pathogens spread by aerosol
  
• Infection serious, possibly lethal
• Examples
• M. tuberculosis
• Coxiella burnetii

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Biohazards in the Work Environment

• Biosafety Guidelines
• Biosafety Level 3 (cont.)
• BLS 2 Facility design PLUS
• Separate building or isolated zone
• Double door entry
• Directional inward airflow
• Single-pass air
• Enclosures for aerosol generating equipment
• Room penetrations sealed
• Walls, floors, ceilings water resistant for
  cleaning
• Work practices same as BSL-2 PLUS
• Work in certified BSC
• Class II or III for infectious material
• Respiratory protection may be indicated
• Decontaminate spills promptly

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Biohazards in the Work Environment

• Biosafety Guidelines
• Biosafety Level 3 (cont.)
• BLS 2 Facility design PLUS
• Vacuum lines protected
• Standard Microbiological Practices
• Supervisor is a competent scientist experienced
  working with agents
• Lab personnel
• Strictly follow guidelines
• Demonstrate proficiency
• Receive appropriate training
• Report incidents
• Participate in medical surveillance

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Biosafety 3 Guidelines
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Biohazards in the Work Environment
Industrial processes
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Biohazards in the Work Environment
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Biohazards in the Work Environment
Industrial Fermentation
For example, Pseudomonas syringae (Sno-Max)