Transcript WASTE MANAGEMENT INDICATORS FOR NATIONAL STATE …

Validation and Monitoring of
Non-burn Health Care Risk
Waste Treatment Facilities in
Gauteng
Linda Godfrey, Dave Baldwin, Martella du Preez,
Pauline Coubrough
Overview
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Introduction
Sterilization versus Disinfection
Approaches and Standards
Case Studies
Testing Standards and Protocols
Evaluation of Efficacy Monitoring
Requirements
Conclusions and Recommendations
Introduction
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South Africa traditionally utilised incineration
Minimum Requirements (DWAF, 1998),
infectious waste must be incinerated or
otherwise sterilised prior to disposal
Ash disposed of to an H:H or H:h landfill
Presents the approach adopted by GDACEL
for validation and monitoring
Sterilization versus Disinfection
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Introduction of new non-burn treatment
technologies
- Heat treatment - microwaving, electro-thermal
de-activation (ETD), autoclaving
- Chemical Treatment – chlorine, ozone
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Non-burn treatment facilities are not typically
required to disinfect health care risk waste
Distinguish between sterilization and
disinfection
Sterilization versus Disinfection
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Sterilisation reduction in microorganisms by one
million (106 or more than 99.9999% are killed)
Low Level Disinfection - most bacteria, some viruses
and some fungi are killed, complete absence of
resistant microorganisms e.g. tubercle bacilli or
bacterial spores cannot be relied on.
Intermediate Level Disinfection - Myocardium
tuberculosis, most viruses and fungi are killed, but
not necessarily bacterial spores.
High-level Disinfection - all microorganisms, with the
exception of small numbers of bacterial spores are
killed.
Increasing resistance to treatment
BACTERIAL SPORES
(e.g. Bacillus Subtilis, Clostridium sporogenes)
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MYCOBACTERIA
(e.g. Mycobacterium tuberculosis var. bovis)
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NON-LIPID OR SMALL VIRUSES
(e.g. Poliovirus, Coxsackie virus, Rhinovirus)
↓
FUNGI
(e.g. Trichophyton spp, Crytococcus spp, Candida spp)
↓
VEGETATIVE BACTERIA
(e.g. Pseudomonas Aeruginosa, Staphylococcus Aureus, Salmonella spp)
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LIPID OR MEDIUM SIZED VIRUSES
(e.g. Herpes Simplex Virus, Cytomegalovirus, Respiratory syncytical virus,
Hepatitis B Virus, Human Immunodeficiency Virus)
Approaches and Standards
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State and Territorial Association on
Alternative Treatment Technologies (STAATT,
1994)
STAATT 1 recommended Level III microbial
inactivation
- inactivation of vegetative bacteria, fungi,
lipophilic/hydrophilic viruses, parasites and
mycobacteria at ≥ 6 Log10 reduction; and
- inactivation of B. stearothermophilus or B.
subtilis spores at ≥ 4 Log10 reduction.
Vegetative Bacteria:
Staphylococcus aureus (ATCC 6538)
Pseudomonas aeruginosa (ATCC 15442)
Fungi:
Candida albicans (ATCC 18804)
Penicillum chrysogenum (ATCC 24791)
Aspergillus niger
Viruses:
MS-2 Bacteriophage (ATCC 15597 – B1)
Parasites:
Cryptosporidium spp. oocysts
Giardia spp. cysts
Mycobacteria:
Mycobacterium terrae
Mycobacterium phlei
Mycobacterium bovis (BCG) (ATCC 35743)
Spores:
Bacillus stearothermophilus (ATCC 7953)
Bacillus subtilis (ATCC 19659)
Approaches and Standards
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STAATT2 (1998) - “the use of additional
biological indicators to demonstrate the
efficiency of treatment systems provides no
additional safeguards to public health and
safety”.
The list of test organisms was reduced to
Mycobacteria and Bacillus spores only,
- inactivation of mycobacteria at ≥6 Log10
reduction, and
- inactivation of B. stearothermophilus or B.
subtilis spores at ≥4 Log10 reduction
International Standards
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Efficacy and monitoring in US States varies:
- STAATT1
- Relaxed STAATT1 (exclusion of parasites)
- STAATT2
- Relaxed STAATT2 (exclusion of mycobacteria)
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Emphasis on parametric monitoring
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Varying monitoring frequency and intervals
South African Standards
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South Africa currently only has draft
guidelines for the validation and efficacy
testing of non-burn treatment facilities
Limited guidance to establishment of nonburn treatment facilities
Reliance on international standards and
approaches for efficacy testing and
monitoring
Case Study 1
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Evertrade Medical Waste, Johannesburg
First non-burn treatment facility in SA, 2002
No SA guidelines for efficacy testing and
monitoring
Gauteng DACEL adopted the conservative
STAATT requirements, i.e. STAATT1
CSIR and National Health Laboratories
Case Study 1
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Minimum, Level III microbial inactivation
One or more biological indicator from each
microbial group:
Fungi
• Candida albicans
Viruses
• MS-2 Bacteriophage
Parasites
• Cryptosporidium
Spores
• Bacillus subtilis
Vegetative Bacteria
• Staphylococcus aureus
Mycobacteria
• Mycobacterium phlei
Problems Experienced
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Availability of organisms in SA
Availability of correct ATCC cultures
- closest ATCC culture
- B. subtilis indicator vials
- importation of viable Cryptosporidium oocysts
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Method of introduction of samples into
treatment process
Medium for sample introduction
Concentrations required for samples
Problems Experienced
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Lack of animal testing facilities for
Cryptosporidium animal infectivity tests
- Percentage viability instead of log reduction
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Laboratory techniques
- Streak Plate Method vs Membrane Filtration
Method for Candida albicans
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Transport methods – B. subtilis
Time frame for validation testing
Results
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All test organisms showed the Stericycle
ETDTM treatment process employed by EMW
Operations to meet the Level III
requirements set by GDACEL of:
- a ≥ 6 Log10 inactivation for vegetative bacteria,
fungi, lipophilic/hydrophilic viruses, parasites and
mycobacteria, and
- a ≥ 4 Log10 reduction for spores.
Case Study 2
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Evertrade Medical Waste, Cape Town
Relaxed standards by Western Cape
Department of Environmental and Cultural
Affairs and Sport, i.e. relaxed STAATT 2
AllkilTM Bacillus subtilis indicators
Reduced testing requirements resulted in
- cost savings for the company and
- reduced the time required for testing by weeks
- without compromising the validity of results
Results
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Testing programme showed 100%
inactivation of Bacillus subtilis spores, i.e.
Level III inactivation required Western Cape
a ≥ 4 Log10 reduction for spores.
Calibrated parametric monitoring, e.g.
temperature, pressure, throughput,
residence time, etc to support monitoring.
Testing Standards and Protocols
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Problems and challenges encountered
Development of Guidelines for Testing
Standards and Protocols for Non-burn Health
Care Risk Waste Treatment Technologies
Identifies 4 testing phases:
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Performance Testing
Regular Testing Programme
Reduced/Routine Testing Programme
Investigative Testing
Testing Standards and Protocols
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Level III inactivation, as a minimum, for all non-burn
technologies, all sizes:
- inactivation of vegetative bacteria, fungi,
lipophilic/hydrophilic viruses, parasites and
mycobacteria at ≥ 6 Log10 reduction; and
- inactivation of B. stearothermophilus or B. subtilis
spores at ≥ 4 Log10 reduction.
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Performance testing programme weekly for a one
month period, i.e. at least 4 times, on “normal”
infectious waste.
The plant must also demonstrate that it can meet
the programme on a challenge load.
Testing Standards and Protocols
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Evaluation of Gauteng draft validation
guidelines
- Proposed monitoring programme: general
assessment
- Performance testing
- Regular testing
- Analytical procedures for efficacy testing
- Availability of analytical facilities in South Africa
- Availability of microbiological organisms in South
Africa
Testing Standards and Protocols
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Cost of implementation
- Testing costs for Large Commercial Facilities
- Testing costs for Small on-site Facilities
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Alternative validation programmes
- Proposed requirements
- Estimated costs
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Comparative costs of various validation
programmes
Cost [R]
Testing Programme
Commercial
Facilities
Small on-site
Facilities
STAATT1: Performance Testing (1)
R260 800
R125 800
STAATT1: Performance Testing (2)
R190 800
R77 800
STAATT2: Performance Testing
R37 750
R15 100
Daily Monitoring (a)
R400 /m
R400 /m
Daily Monitoring (b)
R3 200 /m
R7 200 /m
Monthly Monitoring
R17 000
R7 000
Performance testing scenarios:
(1) Complete STAATT 1 testing
(2) Reduced STAATT 1, excluding parasites
Daily monitoring scenarios:
(a) Suggested Guidelines, i.e. once per day.
(b) Draft Gauteng Guidelines, i.e. every 2 hours
of operation.
Challenges
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The limited availability of required ATCC
organisms in South Africa
The requirements for the importation of
viable Cryptosporidium oocysts for every
validation test
The limited availability of accredited
laboratories in South Africa
The limited availability of qualified individuals
to supervise validation programmes
Challenges
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Interpretation of requirements from
authorities
Interpretation of results by laboratories, the
proponent and authorities
Lack of consistency between Provincial
Authorities in their approach to the
validation of non-burn treatment
technologies
Lack of national guidelines for validation
and monitoring
Conclusions
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Need for capacity to implement and assess
testing programmes
Library of required organisms established at
an accredited laboratory(s)
Relaxation of STAATT 1
As a minimum the exclusion of parasites
Reduction in frequency of regular testing to
once per day
Role of parametric monitoring
The development, implementation and
enforcement of guidelines to support validation
and monitoring of non-burn health care risk
waste treatment facilities, will ensure that these
treatment facilities do not give rise to
environmental and human health risks now or
in the future.