Validation and Monitoring of Non-burn Health Care Risk

Waste Treatment Facilities in Gauteng

Linda Godfrey, Dave Baldwin, Martella du Preez, Pauline Coubrough

Overview

Introduction Sterilization versus Disinfection Approaches and Standards Case Studies Testing Standards and Protocols Evaluation of Efficacy Monitoring

Requirements Conclusions and Recommendations

Introduction

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

Introduction of new non-burn treatment technologies

- Heat treatment - microwaving, electro-thermal de-activation (ETD), autoclaving

- Chemical Treatment – chlorine, ozone Non-burn treatment facilities are not

typically required to disinfect health care risk waste

Distinguish between sterilization and disinfection

Sterilization versus Disinfection 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.

BACTERIAL SPORES (e.g. Bacillus Subtilis, Clostridium sporogenes)

↓MYCOBACTERIA

(e.g. Mycobacterium tuberculosis var. bovis)↓

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)↓

LIPID OR MEDIUM SIZED VIRUSES (e.g. Herpes Simplex Virus, Cytomegalovirus, Respiratory syncytical

virus, Hepatitis B Virus, Human Immunodeficiency Virus)

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Approaches and Standards

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 terraeMycobacterium phleiMycobacterium bovis (BCG) (ATCC 35743)

Spores:Bacillus stearothermophilus (ATCC 7953)Bacillus subtilis (ATCC 19659)

Approaches and Standards 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

Efficacy and monitoring in US States varies:

- STAATT1

- Relaxed STAATT1 (exclusion of parasites)

- STAATT2

- Relaxed STAATT2 (exclusion of mycobacteria)

Emphasis on parametric monitoring Varying monitoring frequency and intervals

South African Standards

South Africa currently only has draft guidelines for the validation and efficacy testing of non-burn treatment facilities

Limited guidance to establishment of non-burn treatment facilities

Reliance on international standards and approaches for efficacy testing and monitoring

Case Study 1

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

Minimum, Level III microbial inactivation

One or more biological indicator from each microbial group:Fungi Vegetative Bacteria

• Candida albicans• Staphylococcus aureus Viruses Mycobacteria• MS-2 Bacteriophage • Mycobacterium phleiParasites• CryptosporidiumSpores• Bacillus subtilis

Problems Experienced

Availability of organisms in SA Availability of correct ATCC cultures

- closest ATCC culture- B. subtilis indicator vials- importation of viable Cryptosporidium

oocysts Method of introduction of samples into

treatment process Medium for sample introduction Concentrations required for samples

Problems Experienced

Lack of animal testing facilities for Cryptosporidium animal infectivity tests

- Percentage viability instead of log reduction Laboratory techniques

- Streak Plate Method vs Membrane Filtration Method for Candida albicans

Transport methods – B. subtilis Time frame for validation testing

Results

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

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

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

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:- Performance Testing- Regular Testing Programme- Reduced/Routine Testing Programme- Investigative Testing

Testing Standards and Protocols 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.

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 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

Cost of implementation- Testing costs for Large Commercial

Facilities

- Testing costs for Small on-site Facilities Alternative validation programmes

- Proposed requirements- Estimated costs

Comparative costs of various validation programmes

Testing Programme

Cost [R]

Commercial Facilities

Small on-site

FacilitiesSTAATT1: 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

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

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

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.