TABLE OF CONTENTS
- OBJECTIVE OF THE PROGRAMME 4
- STRUCTURE OF THE PROGRAMME 4
- COLLABORATORS INVOLVED IN THE PROGRAMME 4
- STAKEHOLDERS INVOLVED IN THE PROGRAMME 4
- LABORATORY TRIALS 5
- FIELD TRIALS 13
1. OBJECTIVE OF THE PROGRAMME
The aim of this programme is to choose technical criteria suitable for tender specification purposes that will make it possible for the South African Department of Health to acquire the equipment and services required for the primary healthcare clinics to perform small incineration for the disposal of medical waste.
2. STRUCTURE OF THE PROGRAMME
The evaluation programme has been carried out in stages, as follows:
Stage 1 A scoping study to determine the obligation of the various parties and
consensus on the evaluation criteria and boundaries of the laboratory tests. The criteria for accepting an incinerator on trial was approved by all parties involved.
Stage two Laboratory tests with a ranking of each incinerator and the choice of the incinerators to be utilised from the field trials.
Stage 3 Completion of field trials, to assess the efficacy of each incinerator under field conditions.
Stage 4 Planning of a tender specification and recommendations to the DoH for the implementation of a continuing incineration programme.
This record provides feedback on stages 2 and 3 of their work.
3. COLLABORATORS INVOLVED IN THE PROGRAMME
SA Collaborative Centre for Cold Chain Management SA National Department of Health
CSIR
Pharmaceutical Society of SA World Health Organisation UNICEF
4. STAKEHOLDERS INVOLVED IN THE PROGRAMME
The following stakeholders engaged in the steering committee:
- Dept of Health (National & provincial levels) (DoH)
- Dept of Occupational Health & Safety (National & provincial levels)
- Dept of Environmental Affairs & Tourism (National & provincial levels) (DEAT)
- Dept of Water Affairs & Forestry (National & provincial levels) (DWAF)
- Dept of Labour (National & provincial levels) (DoL)
- National Waste Management Strategy Group
- SA Local Government Association (SALGA)
- SA National Civics Organisation (SANCO)
- National Education, Health and Allied Workers Union (NEHAWU)
- Democratic Nurses Organisation of SA (DENOSA)
- Medecins Sans Frontieres
- SA Association of Community Pharmacists
- Mamelodi Community Health Committee
- Pharmaceutical Society of SA
- CSIR
- UNICEF
- WHO
- SA Federation of Hospital Engineers
International visitors:
- Dr Luiz Diaz – WHO Geneva and International Waste Management , USA
- Mr Joost van den Noortgate – Medecins Sans Frontieres, Belgium
5. LABORATORY TRIALS
5.1. Objective of the laboratory trials
- Rank the performance of submitted units to the following criteria:
y Occupational safety
y Impact on public health from emissions
y The destruction efficiency
y The usability for its accessible staff
- The panel of experts for the ranking consisted of a:
y Professional nurse; Mrs Dorette Kotze in the SA National Department of Health
y Emission specialist; Dr Dave Rogers in the CSIR
y Combustion Engineer; Mr Brian North in the CSIR
5.2. Incinerators received for evaluation
Name used in report | Model no. | Description | Manufacturer |
C&S Marketing
incinerator |
SafeWaste Model Turbo
2000Vi |
Electrically operated fan supplies combustion air
— no auxiliary fuel |
C&S Marketing cc. |
Molope Gas incinerator | Medcin 400 Medical
Waste Incinerator |
Gas-fired incinerator | Molope Integrated
Waste Management |
Molope Auto incinerator | Molope Auto Medical
Waste Incinerator |
Auto-combust incinerator – uses wood
or coal as additional fuel to facilitate incineration |
Molope Integrated
Waste Management |
Name used in report | Model no. | Description | Manufacturer |
PaHuOy
incinerator |
Turbo Stove | Auto-combust unit,
Working with no additional gas or forced air supply |
Pa-Hu Oy |
5.3. Emission testing: laboratory method
Sampling of emissions followed the US-EPA Method 5G dilution tunnel method for stove emissions. Adjustments to the design were made to account for fires extending up to 0.5 m above the suggestion of the incinerator and the drop out of big pieces of ash. Emissions were extracted to a duct for isokinetic sampling of particulate emissions. The sampling arrangement is shown with a schematic in Figure 1. A photo of this operation within the Molope gas fired incinerator unit is displayed in Figure 2.
All tests were conducted based on specified operating processes. The instructions provided by the provider of the gear were followed in the case of this C&S advertising Unit. No operating procedures were supplied with the Molope Gas, Molope auto-combustion and PaHuOy units. These processes were created by the CSIR staff with their prior experience together with advice provided by the provider.
Evaluation facilities were set up in the CSIR and measurements were carried out under an ISO9001 system using standard EPA test procedures or modifications made in the CSIR.
Figure 1. Schematic diagram of the laboratory set-up
Figure 2:Photograph of air intake sampling hood over Molope gas incinerator
5.4. RANKING RESULTS OF THE LABORATORY TRIALS
Using the criteria listed under section 4.1 above, the incinerators were ranked as followed:
Molope gas-fired
unit |
Molope wood-fired
unit |
C&S electric
unit |
PaHuOy wood-fired
unit |
|
Safety | 6.8 | 4.8 | 5.5 | 3.3 |
Health | 5.5 | 3.5 | 4.3 | 2.3 |
Destruction | 9 | 2 | 6 | 1 |
Usability | 2 | 3 | 3 | 5 |
Average | 5.8 | 3.3 | 4.7 | 2.9 |
5.5. EMISSION RESULTS OF THE LABORATORY TRIALS
Quantitative dimensions were utilized to rank the components Concerning destruction efficiency and also the potential to produce hazardous emissions.
Conformance to the South African Department of Environmental Affairs and Tourism’s (DEAT) urged guidelines on emissions from Large Scale Medical Waste Incinerators is outlined in Table 1. The dimensions are listed1 in Table 2.
Table 1: Summary qualitative results
Parameter Measured | Units | Molope
Gas-fired |
Molope
Wood-fired |
C&S
Electric |
PaHuOy
Wood-fired |
SA DEAT
Guidelines |
Stack height | m | × | × | × | × | 3 m above
nearest building |
Gas velocity | m/s | × | × | × | × | 10 |
Residence time | s | × | × | × | × | 2 |
Minimum combustion
temperature |
ºC | 4 | × | × | × | > 850 |
Gas combustion
efficiency |
% | × | × | × | × | 99.99 |
Particulate emissions | mg/Nm3 | 4 | × | 4 | × | 180 |
Cl as HCl | mg/Nm3 | × | 4 | 4 | × | < 30 |
F as HF | mg/Nm3 | 4 | 4 | 4 | 4 | < 30 |
Metals | mg/Nm3 | 4 | × | × | 4 | < 0.5 and
< 0.05 |
1 Fragrant concentrations are reported in accordance with the South African reporting requirements, ie, normalized to Normal Temperature (0
oC) and Stress (101.3 kPa) and adjusted to a nominal concentration of
8 percent of CO2 on a dry gas basis. If a dimension dropped below the detection limit for the procedure is it reported as the detection limit or as N.D., ie, not detectable.
Table 2: Detailed quantitative results
Parameter Measured * |
Units |
Molope gas |
Molope auto |
C&S |
PaHuOy |
SA Process Guide1 |
Comments |
Stack height |
m |
1.8 |
1.8 |
1.9 |
0.3 |
3 m above nearest building |
None of those unite has a stack. The height of the exhaust vent is taken as the stack height. If it is above the respiration zone of the operator it provides some protection from exposure to smoke. |
Gas speed |
m/s |
0.8 |
0.5 |
1.1 |
0.5 |
10 |
Gas velocities vary across the stack to get its Molope gas, Molope auto-combustion, and also the PaHuOy units. |
Home time |
s |
0.4 |
0.7 |
0.6 |
0.4 |
two |
Home time is taken to be the entire combustion time, along with the maximum possible |
Minimum combustion zone temperature |
oC |
800 -900 |
400 – 650 |
600 – 800 |
500 – 700 |
> 850 |
Molope auto-combustion temperatures are anticipated to become greater as the middle of the combustion zone is not predicted to be in the measurement location. |
CO2 in the stack tip |
percent vol |
2.64 |
3.75 |
4.9 |
3.25 |
8.0 |
Actual emission concentrations are less than the values reported here, that can be normalized to 8 percent CO2 and standard temperature and pressure for coverage purposes. They are reduced between 4 to 8 times. |
Particulate emissions entrained in exhaust gas |
102 |
197 |
130 |
338 |
180 |
The total emissions will be the sum of the both entrained and un- entrained particulates. Emissions are lower than anticipated for such units and this can be attributed to the absence of raking which is the major source of particulate emissions from incinerators with no emission management |
system. |
Combustion | 99.70 | 99.03 | the duct where mixing of exhaust | ||||
efficiency | gases is complete. Results of two
Particulate fall- out |
||||||
42 |
mg/Nm3 |
105 |
n.d. |
n.d. |
– |
Large pieces of paper and cardboard ash rained out of the emissions. Totalling 0.8 to 2 g within a +/- two minute interval. |
Soot in particulates percent |
42.2 |
mg/Nm3 |
58.1 |
48.7 |
84.8 |
– |
Correlates right with gas combustion efficiency |
|
1 Emission concentrations are reported in accordance with the South African coverage requirements, ie, Normalized to Normal Temperature (0 |
oC) and Stress (101.3 kPa) and adjusted to a nominal concentration of |
8 percent of CO2 on a dry gas basis. If a dimension dropped below the detection limit for the procedure is it reported as the detection limit or as N.D., ie, not detectable. |
|
Parameter Measured * |
Units |
Molope gas |
Molope auto |
C&S
PaHuOy
SA Process Guide1
Comments
% ash remaining from medical waste
percent |
14.8 |
12.9 |
15.6 |
21.7 |
– |
Measurement of destruction efficiency of the incinerator. Typical commercial units function in 85-90% mass decrease. PaHuOy is reduced due to the melting and unburnt plastic. |
Cl as HCl |
46 |
13 |
25 |
35 & 542 |
< 30 |
PaHuOy chloride concentrations varied greatly. This is expected as a result of the variability of the feed composition. |
F as HF |
< 6 |
< 1 |
mg/Nm3 |
<2 |
< 1 |
< 30 |
Fluoride not found in this waste. |
Arsenic (As) |
< 0.2 |
< 0.2 |
mg/Nm3 |
< 0.2 |
< 0.2 |
0.5 |
Arsenic is not anticipated as a strong. Higher sensitivity not hunted with this trial. |
Chromium (Cr) |
< 0.1 |
0.7 |
mg/Nm3 |
0.7 |
< 0.1. |
0.5 |
Chromium comparative to iron ranges between 12 and 25% which is consistent with stainless steel needles |
Manganese (Mn) |
< 0.1 |
0.3 |
mg/Nm3 |
0.3 |
< 0.1 |
0.5 |
Manganese might be a part from the stainless steel needle. |
Nickel (Ni) |
< 0.1 |
0.3 |
mg/Nm3 |
< 0.1 |
< 0.1 |
0.5 |
Nickel may be a part from the needle. |
Barium (Ba) |
< 0.5 |
< 0.5 |
mg/Nm3 |
< 0.5 |
< 0.5 |
0.5 |
Lower sensitivity due to presence in the filter material |
Silver (Ag) |
< 0.2 |
< 0.2 |
mg/Nm3 |
< 0.2 |
< 0.2 |
0.5 |
Not anticipated in this waste. |
Copper (Cu) |
< 0.5 |
< 0.5 |
mg/Nm3 |
< 0.5 |
< 0.5 |
0.5 |
Lower sensitivity due to copper from the sample blanks. May be background from the analytical equipment. Sensitivity of this x-ray way is sufficient for position. Higher sensitivity not hunted with this trial. |
|
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|
mg/Nm3 |
|
The principal conclusions drawn in the trials are as follows: |
|
::: All four components may be utilized to leave medical waste non-infectious, and to ruin syringes or leave needles unsuitable for reuse. |
::: The largest potential health hazard arises in the emissions of smoke and soot. (the combustion efficiency of units lies away from the |
regulatory criteria ). The risk to health can be reduced by training operators to avoid the smoke or by installation of a chimney in the website. |
::: The emissions from small scale incinerators are predicted to be lower compared to those from a wood fire, but greater than a traditional fire-brick- |
mg/Nm3 |
lined multi-chambered incinerator. |
::: Incomplete combustion, along with the substantial formation of smoke at reduced height rendered the PaHuOy unit unacceptable for field trials. Figure 3 |
below shows this unit during a trial burn. Molten plastic flowed out of |
the incinerator, blocked the primary combustion air feed vents, and burnt out of the unit. |
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|
mg/Nm3 |
|
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|
The CSIR conducted a qualitative trial in the field for gas combustion efficiency, temperature profiles and mass destruction rate on the Molope Vehicle wood-fired unit in the Mogale Clinic. |
|
The outcomes of this trial are contrasted to the laboratory trial outcomes below: |
|
mg/Nm3 |
Temperatures were greater but for a shorter time and this was |
connected with the type of wood available to this practice. The gas was burnt out before the medical waste was ruined completely and this caused reduced temperatures, reduced combustion efficiency and greater emissions while reducing the waste. |
before complete ignition of the waste. |
|
It was reasoned that: |
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|
mg/Nm3 |
|
|
these recommendations are made as the result of the laboratory trials: |
::: A detailed operating manual must be supplied with each unit. |
Adequate training in the operation of these units have to be supplied, especially focussed on safety difficulties. |
::: It is recommended that the height of the exhaust vent on all components be |
addressed. To be able to facilitate the dispersion of emissions and lessen the vulnerability risk of these operators. |
mg/Nm3 |
::: The suppliers of this incinerators must supply instructions for its safe handling and disposal of ash. |
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|
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|
mg/Nm3 |
After completion of the laboratory trials, the project steering committee urged that the Molope Gas and C&S Marketing units be submitted for field testing. The Molope Vehicle was advocated for field testing on the condition that the manufacturer altered the ash grate so as to prevent the spillage of partly burned off needles and syringes. |
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The aim of this field trials would be to acquire information in the field and assess the strengths and weaknesses of all the incinerators during usage at primary healthcare clinics. |
mg/Nm3 |
|
A participative decision making process was utilized for its trials. It was based on expert technical analysis from the CSIR and the National Department of Health in addition to involvement in the trials by experienced end users and engaging advisors. All decisions were made by the Steering Committee, which consisted of representatives of stakeholders in the medical and clinical waste disposal process. These included representatives from the National, Provincial, and Local Government departments of Health, Safety and the Environment, in Addition to Professional Associations, Unions, NGOs, UNICEF, the WHO and local community representatives. |
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The Provinces in which the trials were done chosen clinics for its field trials. The criteria set by the Steering Committee for the choice of the clinics were the following: |
|
y No medical waste removal
y No existing incineration
y No transport
5.6. MAIN FINDINGS OF THE LABORATORY TRIALS
The clinics that were chosen were as follows:
incinerator, wood-fired.
incinerator
MAP OF SOUTH AFRICA INDICATING WHERE THE CLINICS ARE SITUATED
Figure 3: Photo of PaHuOy incinerator during trial burn
5.7. COMPARISON OF THE FIELDS TRIALS WITH THE LABORATORY TRIALS
- Waste loading: Disposable rubber gloves were observed in addition to needles syringes, glass vials, bandages, dressings, and paper w
- Temperatures and combustion efficiency: The same performance in gas combustion efficiency was obtained for wood .
NORTHERN PROVINCE
- Emissions: Large amounts of black smoke were observed and this was correlated directly to cooling of the unit as the wood fuel was exhausted
- Destruction efficiency: The destruction efficiency was similar to that in the laboratory measurem
- Usability: The unit is difficult to control as the result of the variability of the quality of wood
- Acceptability: the smoke was not acceptable to the clinic, the community, or the local
GAUTENG PROVINCE
- The performance with fuel alone indicates that laboratory trial data can be used to predict emissions in the
- The Molope Auto unit is too difficult to control for the available staff and fuel at the
5.8. RECOMMENDATIONS FROM THE LABORATORY TRIALS
NORTH WEST PROVINCE
MPUMALANGA PROVINCE
FREE STATE PROVINCE
5.9. RECOMMENDATIONS FROM THE STEERING COMMITTEE
NORTHERN CAPE PROVINCE
KWAZULU-NATAL PROVINCE
6. FIELD TRIALS
6.1. OBJECTIVE OF THE FIELD TRIALS
6.2. CLINIC SELECTION
- Location must be rural or under-serviced with
- It must be in a high-density population area
- Acceptable environmental conditions must prevail
- Community acceptance must be obtained
- Operator skill level to be used must be at a level of illiteracy
- Steinkopf Clinic – Northern Cape Province – Gas incinerator
- Marydale Clinic – Northern Cape Province – Gas incinerator
- Mogale Clinic – Gauteng Province – Auto combustion
- Chwezi Clinic – KwaZulu-Natal Province – Gas incinerator
- Ethembeni Clinic- KwaZulu-Natal Province – Auto-combustion electrical
I:/UnitPublic/Valerie/Technet 99/Working papers/Session 3/rogers.doc
EASTERN CAPE PROVINCE
WESTERN CAPE PROVINCE
|
6.3. COORDINATION OF THE TRIALS
- Safety (occupational and public health)
- Destruction capability
- Usability
- Community acceptability
Considered user-friendly by operator, supervisor and inspector.
The incinerator was approved by the community and wasn’t regarded as harmful.
Sort of incinerator: Molope Gas incinerator
A. SAFETY (occupational and public health)
- Smoke Emission
- Ash Content
- Are the filled sharps boxes and soiled dressings stored in a locked location while waiting to be incinerated?
B. DESTRUCTION CAPABILITY
- Destruction Rate
This incinerator was believed user friendly.
C. USABILITY (for the available staff)
- Can the incinerator be used easily?
- Is the process of incineration safe?
- Has training been successful?
- Is protective clothing such as gloves, goggles, dust masks and safety boots available?
The incinerator was approved by the community and wasn’t regarded as harmful.
D. COMMUNITY ACCEPTABILITY
- What is the opinion of the following persons on the use of the incinerator?
Two
timber, coal also an alternative )
3
6.4. QUESTIONNAIRE RESULTS
6.4.1. MOGALE CLINIC
(Uses Electricity)
Great
Great
Great
Great
Combust Incinerator
Figure 4 & 5: Molope Auto wood-fired incinerator during field trials at Mogale clinic
A. SAFETY (occupational and public health)
- The process of incineration with this unit was considered by the operator, supervisor and the inspector as unsafe because there is no protective cage around the During the process the incinerator becomes very hot and this could result in injury to the operator.
- The smoke emission of this incinerator had a volume and thickness which was heavy and black, with a distinct unpleasant odour, and was considered This could cause a pollution problem.
B. DESTRUCTION CAPABILITY
- The needles and vials were not completely destroyed but were rendered unsuitable for re-use.
- The soft medical waste was completely destroy
C. USABILITY
Difficulty in controlling the operating temperature and avoiding smoke emissions made this incinerator user unfriendly.
D. COMMUNITY ACCEPTABILITY
As a result of the heavy, black smoke emission the unit was not acceptable to the community.
6.4.2. ETHEMBENI CLINIC:
Figure 6: C&S Marketing Auto Combust Electrical Incinerator At Ethembeni Clinic
Type Of Incinerator: C&S Auto-Combustion (Uses an electrically actuated fan)
A. SAFETY (occupational and public health)
- The operator, supervisor and inspector considered this incinerator easy to operate with no danger to the Removal of the ash from the drum for disposal in a pit is, however, considered difficult, as the drum is heavy. Removal of the incinerator lid before it has been allowed to cool has been identified as a potential danger to the operator.
- Emission of smoke from this incinerator was not considered ex The volume and thickness was evaluated as moderate with no pollution experienced.
B. DESTRUCTION CAPABILITY
- The needles and vials were not completely destroyed but were rendered unsuitable for re-use.
- The soft medical waste was completely destroy
C. USABILITY
Considered user friendly by operator, supervisor and inspector.
D. COMMUNITY ACCEPTABILITY
The incinerator was accepted by the community and was not considered to be harmful.
6.4.3. CHWEZI CLINIC, MARYDALE CLINIC AND STEINKOPF CLINIC:
Type of incinerator: Molope Gas incinerator
Figure 7: Molope Gas incinerator during field trials at Marydale clinic
A. SAFETY (occupational and public health)
- The operator, supervisor and inspector considered this incinerator easy to operate with minimal danger to the
- Smoke emissions were not excessive and were reported to be minim
B. DESTRUCTION CAPABILITY
- Sharps not completely destroyed but were rendered unsuitable for re-use.
- Soft medical waste completely destroy
C. USABILITY
This incinerator was considered user friendly.
D. COMMUNITY ACCEPTABILITY
The incinerator was accepted by the community and was not considered to be harmful.
6.5. RANKING
INCINERATOR | RANKING |
Molope Gas | 1 |
C&S Auto-Combustion (Uses electrical fan) |
2 |
Molope Auto- Combustion (Fired with
wood, coal also an option) |
3 |
6.6. OUTCOME OF THE FIELD TRIALS
Incinerator | Safety | Destruction Capability | Usability | Community Acceptability |
Molope Gas | Good | Good | Good | Good |
C&S Auto- Combustion
(Uses Electricity) |
Good |
Good |
Good |
Good |
Molope Auto-
Combust Incinerator |
Un-Acceptable | Good | Un-Acceptable | Un-Acceptable |