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Programme on Small Scale Medical Waste Incinerators for Primary Health Care Clinics in South Africa

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Programme on Small Scale Medical Waste Incinerators for Primary Health Care Clinics in South Africa

TABLE OF CONTENTS

  1. OBJECTIVE OF THE PROGRAMME 4
  2. STRUCTURE OF THE PROGRAMME 4
  3. COLLABORATORS INVOLVED IN THE PROGRAMME 4
  4. STAKEHOLDERS INVOLVED IN THE PROGRAMME 4
  5. LABORATORY TRIALS 5
  6. FIELD TRIALS 13

 

 

 

1.     OBJECTIVE OF THE PROGRAMME

 

The aim of this programme is to choose technical standards suitable for tender specification functions that will make it possible for the South African Department of Health to acquire the equipment and services necessary for the primary healthcare practices to perform small incineration for the disposal of medical waste.

 

2.     STRUCTURE OF THE PROGRAMME

 

The evaluation programme is being completed in stages, as follows:

Phase 1         A scoping study to determine the obligation of the various parties and

consensus on the evaluation criteria and boundaries of the lab tests. The standards for accepting an incinerator on trial has been approved by all parties involved.

Phase 2         Laboratory tests with a ranking of each incinerator and the selection of the incinerators to be used in the field trials.

Phase 3         Completion of field trials, to assess the effectiveness of each incinerator under field conditions.

Phase 4         Preparation 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 job.

 

 

 

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 security

y Impact on public health from emissions

y The destruction efficiency

y The usability for the accessible staff

 

  • The panel of experts for the ranking consisted of a:

y Professional nurse; Mrs Dorette Kotze from the SA National Department of Public Health

y Emission specialist; Dr Dave Rogers from the CSIR

y Combustion Engineer; Mr Brian North from 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 extra fuel to ease incineration

Molope Integrated

Waste Management

 

Name used in report Model no. Description Manufacturer
PaHuOy

incinerator

Turbo Stove Auto-combust unit,

Working with no additional fuel or pressured air source

Pa-Hu Oy

 

 

5.3.   Emission testing: laboratory method

 

Sampling of emissions followed the US-EPA Method 5G dilution tunnel Way of stove emissions. Adjustments to the design were created to account for fires extending around 0.5 m over the tip 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 revealed with a schematic in Figure 1. A photograph of this performance over the Molope gas fired incinerator unit is shown in Figure 2.

 

All tests were performed based on specified operating processes. The instructions provided by the supplier of the gear were followed in the case of this C&S advertising Unit. No working procedures were provided with the Molope Gas, Molope auto-combustion and PaHuOy units. These processes were created by the CSIR personnel with their prior experience together with information provided by the supplier.

 

Test facilities were put up in the CSIR and measurements have been completed 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 standards listed under section 4.1 above, the incinerators were rated 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 measurements were used to rank the components Concerning destruction efficiency and also the potential to produce poisonous emissions.

 

Conformance to the South African Department of Environmental Affairs and Tourism’s (DEAT) recommended guidelines on emissions from Large Scale Medical Waste Incinerators is summarized in Table 1. The measurements 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

performance

% × × × × 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 Regular Temperature (0

oC) and Pressure (101.3 kPa) and corrected to a minimal concentration of

8% of CO2 to a dry gas basis. If a measurement fell below the detection limit for the method is it either 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 Procedure Guide1

 

Comments

 

Stack height

 

m

 

1.8

 

1.8

 

1.9

 

0.3

 

3 m over nearest building

 

none of those unite has a stack. The height of the exhaust vent is taken as the pile height. When it is over the respiration zone of the operator it provides some protection from exposure to smoke.

 

Gas velocity

 

m/s

 

0.8

 

0.5

 

1.1

 

0.5

 

10

 

Gas velocities change across the pile for the Molope gasoline, Molope auto-combustion, and also the PaHuOy units.

 

Residence time

 

s

 

0.4

 

0.7

 

0.6

 

0.4

 

2

 

Residence time is regarded as the total combustion time, and the maximum achievable

 

Minimum combustion zone temperature

oC  

800 -900

 

400 – 650

 

600 – 800

 

500 – 700

 

> 850

 

Molope auto-combustion temperatures are anticipated to be higher as the middle of the combustion zone is not predicted to be in the measurement location.

 

CO2 in the stack tip

 

% vol

 

2.64

 

3.75

 

4.9

 

3.25

 

8.0

 

Actual emission concentrations are less than the values reported here, that are normalized to 8% CO2 and standard temperature and pressure to reporting functions. They’re reduced between 4 to 8 times. Emissions are lower than anticipated for these 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.

 

Particulate fall- out

 

42

 

105

 

n.d.

 

n.d.

 

 

Large pieces of paper and cardboard ash rained out of the emissions. Totalling 0.8 to 2 g over a +/- 2 minute interval.

Combustion 99.70 99.03 the duct where mixing of exhaust
efficiency gases is complete. Results of two

Soot at particulates

 

%

mg/Nm3  

42.2

 

58.1

 

48.7

 

84.8

 

 

Correlates directly with gasoline combustion efficiency

 

 

1 Emission concentrations are reported in accordance with the South African coverage requirements, ie, Normalized to Regular Temperature (0

mg/Nm3  

oC) and Pressure (101.3 kPa) and corrected to a minimal concentration of

 

8% of CO2 to a dry gas basis. If a measurement fell below the detection limit for the method is it either reported as the detection limit or as N.D., ie, not detectable.

 

 

 

Parameter Measured *

 

Units

 

Molope gas

 

Molope auto

 

C&S

 

PaHuOy

 

SA Procedure Guide1

 

Comments

 

% ashes remaining from clinical waste

 

%

 

14.8

12.9

15.6

21.7

Measurement of destruction efficiency of the incinerator. Typical commercial units operate in 85-90% mass decrease. PaHuOy is reduced due to the melting and unburnt plastic. This is expected due to the variability of the feed composition.

 

Lead (Pb)

 

< 0.4

 

< 0.4

 

< 0.4

 

< 0.4

 

0.5

 

Lead maybe not anticipated in waste

 

Cadmium (Cd)

 

< 0.2

 

< 0.2

 

< 0.2

 

< 0.2

 

0.05

 

Sensitivity of this x-ray method is sufficient for ranking. Greater sensitivity not sought 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% that’s consistent with stainless steel needles

 

Manganese (Mn)

 

< 0.1

 

0.3

mg/Nm3  

0.3

 

< 0.1

 

0.5

 

Manganese might be a component in the stainless steel needle.

 

Nickel (Ni)

 

< 0.1

 

0.3

mg/Nm3  

< 0.1

 

< 0.1

 

0.5

 

Nickel may be a component in the needle.

 

Antimony (Sb)

 

< 0.2

 

< 0.2

mg/Nm3  

< 0.2

 

< 0.2

 

0.5

 

Not anticipated in this waste.

 

Barium (Ba)

 

< 0.5

 

< 0.5

mg/Nm3  

< 0.5

 

< 0.5

 

0.5

 

Reduced 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

 

Reduced sensitivity due to aluminum in the sample blanks. May be background in the analytical equipment.

 

Vanadium (V)

 

< 0.1

 

< 0.1

mg/Nm3  

0.4

 

< 0.1

 

0.5

 

Vanadium may be within stainless steel. Sensitivity of this x-ray method is sufficient for ranking. Greater sensitivity not sought with this trial.

 

 

 

 

 

 

mg/Nm3  

 

 

The principal conclusions drawn from the trials are as follows:

 

 

 

:::          All four components can be used to leave medical waste non-infectious, and to ruin syringes or leave needles unsuitable for reuse.

 

:::                           The biggest potential health hazard originates from the emissions of smoke and soot.              (the combustion efficiency of units lies away from the

 

regulatory standards). The threat to health can be reduced by training operators to steer clear of the smoke or by installation of a chimney in the website.

 

:::          The emissions from small scale incinerators are predicted to be lower than those from a wood fire, but higher than a traditional fire-brick-

mg/Nm3  

lined multi-chambered incinerator.

 

:::          Incomplete combustion, and the substantial formation of smoke at reduced height left 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 outside of the unit.

 

 

 

 

 

 

mg/Nm3  

 

 

 

 

 

 

The CSIR performed a quantitative trial in the field for gasoline combustion efficiency, temperature profiles and mass destruction speed on the Molope Vehicle wood-fired unit in the Mogale Clinic.

 

 

 

The results of this trial are compared to laboratory trial results below:

 

 

mg/Nm3  

Temperatures were higher but for a shorter time and this was

 

correlated with the kind of wood available to this clinic. The gas has been burnt out before the medical waste was destroyed entirely and this resulted in reduced temperatures, reduced combustion efficiency and higher emissions while burning the waste.

 

before complete ignition of the waste.

 

 

 

It was reasoned that:

 

 

 

 

mg/Nm3  

 

 

 

 

these recommendations are created as the result of the lab trials:

 

:::     A detailed operating manual must be provided with each unit.

 

Adequate training in the performance of the units have to be provided, particularly focussed on security issues.

 

:::     It is suggested that the height of the exhaust vent on all components be

 

addressed.     In order to facilitate the dispersion of emissions and reduce the exposure risk of the operators.

mg/Nm3  

:::     The suppliers of this incinerators must supply instructions for the safe management and disposal of ashes.

 

 

 

 

 

 

 

 

 

 

 

 

mg/Nm3  

After conclusion of the lab trials, the project steering committee recommended the Molope Gas and C&S Marketing units be submitted for field testing. The Molope Vehicle was advocated for field testing on the state that the manufacturer modified the ash grate in order to stop the spillage of partly burned off needles and syringes.

 

 

 

 

 

 

 

 

 

 

 

The aim of this field trials was to acquire information within the field and assess the strengths and weaknesses of each of the incinerators during usage at primary healthcare practices.

mg/Nm3  

 

 

A participative decision making procedure was used for the trials. It was based on specialist technical evaluation from the CSIR and the National Department of Health as well as involvement in the trials by experienced end users and participating advisors. All decisions were made by the Steering Committee, which consisted of representatives of stakeholders in the medical and clinical waste disposal procedure.

 

 

 

 

 

The Provinces where the trials were performed chosen clinics for the field trials. The standards determined by the Steering Committee for the selection of the practices were the following:

 

 

y No clinical waste elimination

y No existing incineration

y No transportation

5.6.   MAIN FINDINGS OF THE LABORATORY TRIALS

 

The practices that were chosen were as follows:

 

 

 

incinerator, wood-fired.

 

Information concerning the field trials as well as surveys were provided to the coordinators in the participating states.

 

The group in the field consisted of this operator, manager and inspector (planner ). The manufacturer of this incinerators did the practice of those operators.

 

The questionnaires used during the trials have been set in order to receive information with regard to the standards set for the standing of their incinerators according to performance within the field. The questionnaires were received from the clinics in two-weekly intervals.

 

Queries Concerning the standards were the following:

Figure 3: Photo of PaHuOy incinerator during trial burn

 

 

5.7.   COMPARISON OF THE FIELDS TRIALS WITH THE LABORATORY TRIALS

y Volume and depth

y Colour

y Odour

 

 

  • 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    .

 

 

  • Emissions: Large amounts of black smoke were observed and this was correlated directly to cooling of the unit as the wood fuel was exhausted

y Total

  • 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

y Partial

y Minimal

  • 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

y Residue articles

 

 

5.8.   RECOMMENDATIONS FROM THE LABORATORY TRIALS

 

 

 

y Operator

y Nurse

y Head of this clinic

y Local Authority representative

y Community leader

 

Throughout the trials the practices were visited and the incinerators evaluated by members of the Steering Committee and the CSIR in Addition to Dr L Diaz from WHO, Mr M Lainejoki from UNICEF and the planner from the National Department of Public Health.

5.9.   RECOMMENDATIONS FROM THE STEERING COMMITTEE

 

 

As a consequence of the thick, dark smoke emission the unit was not appropriate to the community.

 

 

 

 

6.     FIELD TRIALS

 

6.1.   OBJECTIVE OF THE FIELD TRIALS

 

 

Sort Of Incinerator: C&S Auto-Combustion (Uses an electrically actuated enthusiast )

 

 

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

Considered user-friendly by operator, manager and inspector.

  • Chwezi Clinic – KwaZulu-Natal Province – Gas incinerator
  • Ethembeni Clinic- KwaZulu-Natal Province – Auto-combustion electrical

 

 

The incinerator was approved by the community and was not considered to be harmful.

 

 

 

 

Sort of incinerator: Molope Gas incinerator

 

 

 

 

 

 

 

 

 

This incinerator was believed user friendly.

 

 

 

 

 

 

The incinerator was approved by the community and was not considered to be harmful.

 

 

 

 

 

2

wood, coal also an alternative )

3

 

 

 

 

 

(Uses Electricity)

Good

 

Good

Good

Good

Combust Incinerator

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I:/UnitPublic/Valerie/Technet 99/Working papers/Session 3/rogers.doc

 

 

 

EASTERN CAPE PROVINCE

 

 

WESTERN CAPE PROVINCE

 

 

6.3.   COORDINATION OF THE TRIALS

 

The criteria for the ranking of the incinerators in accordance with performance in the field were:

 

  • Safety (occupational and public health)
  • Destruction capability
  • Usability
  • Community acceptability

 

The South African National Department of Health coordinated the field trials.

 

Information regarding the field trials as well as questionnaires were supplied to the coordinators in the participating provinces.

 

The team in the field consisted of the operator, supervisor and inspector (coordinator). The manufacturer of the incinerators did the training of the operators.

 

The questionnaires used during the trials were set so as to obtain information with regard to the criteria set for the ranking of the incinerators in accordance with performance in the field. The questionnaires were received from the clinics at two-weekly intervals.

 

Questions with regard to the criteria were the following:

 

A.  SAFETY (occupational and public health)

 

  • Smoke Emission

y Volume and thickness

y Colour

y Odour

  • 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

y Complete

y Partial

y Minimal

y Residue content

 

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?

 

D.  COMMUNITY ACCEPTABILITY

 

  • What is the opinion of the following persons on the use of the incinerator?

y Operator

y Nurse

y Head of the clinic

y Local Authority representative

y Community leader

 

During the trials the clinics were visited and the incinerators evaluated by members of the Steering Committee and the CSIR as well as Dr L Diaz from WHO, Mr M Lainejoki from UNICEF and the coordinator from the National Department of Health.

 

6.4.   QUESTIONNAIRE RESULTS

 

6.4.1.      MOGALE CLINIC

 

Type of incinerator at the clinic: Molope Auto-Combustion (Fired with wood)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 4 & 5: Molope Auto wood-fired incinerator during field trials at Mogale clinic

 

 

A.               SAFETY (occupational and public health)

 

  1. 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.

 

  1. 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

 

  1. The needles and vials were not completely destroyed but were rendered unsuitable for re-use.

 

  1. 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)

 

  1. 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.

 

  1. 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

 

  1. The needles and vials were not completely destroyed but were rendered unsuitable for re-use.
  2. 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)

 

  1. The operator, supervisor and inspector considered this incinerator easy to operate with minimal danger to the
  2. Smoke emissions were not excessive and were reported to be minim

 

B.               DESTRUCTION CAPABILITY

 

  1. Sharps not completely destroyed but were rendered unsuitable for re-use.

 

 

  1. 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