Ministry of Housing,
Spatial Planning and the Environment
Directorate General for Environmental Protection
Rijnstraat 8
P.O. Box 30945
Guideline Hospital Waste
Decontamination Equipment
December 2006
VROM 7098 – februari 2007
2500 GX The Hague, The Netherlands
Internal Postal Code 645
Contents
1
Preface
4
2
2.1
2.2
Introduction
Sterilization or disinfection
Batch versus continuous processing
5
5
5
3
Scope
6
4
Definitions
7
5
5.1
5.2
5.2.1
5.2.2
5.2.3
5.2.4
Process
Decontamination agent
Decontamination process
Shredding waste and/or removing air
Wetting and heating
Decontamination
Drying (when required)
9
9
9
9
10
10
10
6
6.1
6.2
6.3
Equipment
General
Process
Monitoring, control, faults and maintenance
11
11
12
12
7
7.1
7.2
7.3
7.4
7.5
7.6
7.7
Validation
Type test
Works test
Installation qualification (IQ)
Operational qualification (OQ)
Performance qualification (PQ)
Report
Requalification
14
14
15
15
15
15
15
16
8
8.1
8.2
Routine monitoring and release of processed waste
Process documentation
Release of processed waste
17
17
17
9
Literature
18
Annex 1: Rationale for the decontamination process parameters
19
Annex 2: Correlation between temperature and pressure in saturated steam
21
Annex 3: Validation – Schematic representation
22
Annex 4: Persons involved in drawing up the guideline
22
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1
Preface
Every health-care facility produces waste that contains pathogenic micro-organisms which makes it
potentially hazardous for humans. This type of waste is referred to as ‘hospital waste’. In the Netherlands,
hospitals are not allowed to discard hospital waste as normal industrial waste. Legal reasons aside (Wet
Milieubeheer, Landelijk Afvalbeheersplan), a hospital may choose, for aesthetic reasons, to decontaminate
hospital waste before transporting it to a regional waste incinerator.
The requirements for the efficacy and reproducibility of the decontamination process of hospital waste
show a strong resemblance to the requirements for the disinfection and sterilization of reusable medical
devices. There are, however, two important differences:
• The level of contamination of the hospital waste is expected to be very high.
• There is no concern about the compatibility between the products that are decontaminated and the
process; the process may be destructive for the products.
It is common practice to collect injection needles in sharps containers and incinerate them in the Dutch
central hospital waste incinerator in Dordrecht (ZAVIN). The ideal hospital waste decontamination
equipment is able to render injection needles harmless and unrecognizable. Not all of the equipment that is
currently available on the market is designed to process sharps. A manufacturer claiming that its
decontamination equipment is able to process sharps is required to univocally substantiate its claim.
The design and construction of hospital waste decontamination equipment vary considerably. For these
reasons, not all of the requirements in Section 6 of this guideline may be applicable. Manufacturers shall
provide a rationale for every requirement it does not deem applicable to its decontamination equipment.
Moreover, manufacturers shall demonstrate that the decontamination process effectively and reproducibly
disinfects or sterilizes the hospital waste.
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1
1.1
Introduction
Sterilization or disinfection
In the autumn of 2005, at the request of the Netherlands Ministry of Housing, Spatial Planning and the
Environment, the RIVM conducted a study to establish which methods are suitable to decontaminate
hospital waste. The study showed that disinfection or sterilization with moist heat is the most suitable
method. Both the efficacy and reproducibility are high for moist heat processes that use hot water and/or
saturated steam. Annex 1 provides a summary of the relevant parts of the study report.
1.2
Batch versus continuous processing
Decontamination processes can be run in individual batches or continuously. The requirements in this
guideline apply to both techniques.
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2
Scope
This guideline describes the requirements for the equipment and the process for the decontamination of
hospital waste that use saturated moist heat.
Readers are advised to contact the waste disposal service for possible additional requirements. It must be
clear whether the output from a decontamination unit will be accepted by the waste disposal service before
purchasing equipment.
Note: It is not the intention of this guideline to exclude decontamination techniques that do not use saturated moist heat. For such
techniques, this guideline can be used as a reference, whereby the applicability of each requirement in this guideline must be
evaluated. Where necessary, manufactures will provide additional information confirming the requirements, and in particular, the
requirements concerning the efficacy of the process.
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3
Definitions
For the purpose of this guideline, the following definitions apply:
Decontaminate
The processing of hospital waste using saturated moist heat in order to inactivate infectious agents;
disinfection or sterilization.
Decontamination process
A series of (automated) actions carried out to decontaminate hospital waste, including pre-treatment (for
example, conditioning and shredding) and post-treatment (drying).
Decontamination time
The time necessary to achieve the specified process efficacy under the defined process conditions.
Disinfection
The inactivation of the micro-organisms that pose a risk of infection. This does not necessarily mean all
micro-organisms.
Equilibration time
The period which elapses between the attainment of the decontamination temperature at the temperature
sensor of the process controller and the attainment of the sterilization temperature at all points within the
load.
Hospital waste
Waste from maternity care, wound treatment, diagnosis and the treatment or prevention of diseases in
humans and/or related examinations, the collection and disposal of which is bound by rules to prevent the
spreading of disease and infection. This type of waste is categorized by Eural as category 18.01.03.
Installation qualification (IQ)
The process of obtaining and documenting evidence that equipment has been provided and installed in
accordance with its specification.
Operational qualification (OQ)
The process of obtaining and documenting evidence that installed equipment operates within
predetermined limits when used in accordance with its operational procedures.
Performance qualification (PQ)
The process of obtaining and documenting evidence that equipment that is installed and operated in
accordance with operational procedures consistently performs in accordance with predetermined criteria
and thereby yields product that meets its specifications.
Process Challenge Device (PCD)
An item designed to constitute a defined resistance to a sterilization process and used to assess the
performance of the process.
Note: The item is designed to receive a biological or chemical indicator in the part that is most difficult to penetrate by the moist heat.
The composition of the hospital waste may determine the design of the PCD.
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Process parameter
Specified value for a process variable.
Process variable
A condition in a sterilization process, changes in which alter microbicidal effectiveness.
Examples: Time, temperature, pressure, concentration, humidity.
Reproducible
A decontamination process is reproducible when the critical process parameters in every process run are
within the specified tolerances.
Saturated moist heat
a. Water vapour that is in a state of equilibrium between condensation and evaporation.
Note: See Annex 2 for the mathematical correlation between the temperature and the
pressure of water vapour.
b. Liquid water with a temperature of at least 65°C.
Self-decontamination cycle
A decontamination cycle designed to decontaminate the internal parts of the equipment, which, during
normal use, come into contact with the hospital waste being processed, in order to render these parts safe
to handle for maintenance and repairs.
Sterilization
Validated process used to render a product free from viable micro-organisms.
Temperature band
The range of temperatures measured during the decontamination time, the minimum of which is the
decontamination temperature and the maximum of which is specified by the manufacturer.
Theoretical steam temperature
The temperature of saturated steam calculated from the prevailing pressure.
Type test
A series of checks and tests for a particular design of decontamination equipment that demonstrate
compliance with the requirements of this guideline.
Note: This series of checks and tests is performed by the manufacturer before the equipment is marketed. The user of the equipment
can use the data from the type test to determine whether the decontamination equipment is suitable for the intended purpose.
Validation
The documented procedure for obtaining, recording and interpreting the results required to establish that a
process will consistently yield product that complies with predetermined specifications.
Note: IQ, OQ and PQ are part of the validation process. See Annex 3 for a schematic representation of the relationship between the
different procedures.
Waste disposal service
A legal entity that collects decontaminated hospital waste from the hospital.
Works test
A series of tests performed at the manufacturer’s works to demonstrate that each decontamination
apparatus complies with its specifications.
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4
4.1
Process
Decontamination agent
The decontamination equipment described in this guideline uses saturated moist heat to inactivate
hazardous micro-organisms. Saturated moist heat can be used in the form of steam or liquid water, both of
which are equally effective in the inactivation of micro-organisms. The hospital waste can either be
submerged in hot water or be exposed to externally generated steam that is admitted into the
decontamination vessel. Moist heat can also be generated from the water that is already present in the
waste materials, for example, bottles of growth media from the laboratory, by heating the water with steam,
micro-waves, compression, etc.
It is essential that both moisture and heat are present on the surfaces to be decontaminated. In the event
that some surfaces are not readily exposed to the moist heat, for example, in tubes and injection needles,
additional means shall be used to make the surfaces accessible to moist heat. Common techniques to
achieve this consist of shredding the waste or removing the air by vacuum, or a combination of both.
Based on these principles, a range of technical solutions to produce an effective decontamination cycle for
each of the specified types of hospital waste may be developed, each with its own advantages and
disadvantages.
The time and temperature combinations specified in Clause 6 for acceptable disinfection and sterilization
processes are only valid for saturated moist heat as the decontamination agent (see also Annex 1). On the
surfaces to be decontaminated, the measured temperature shall correspond to the theoretical steam
temperature. Annex 2 provides the correlation between the temperature and the pressure of saturated
steam. In the event that these criteria are not met, the moist heat will not be saturated and the
decontamination times stated in Clause 6 will not be valid. In such cases, the manufacturer is required to
demonstrate, for example, by microbiological testing, that the process is effective despite the nonsaturated conditions of the moist heat.
4.2
Decontamination process
The decontamination process shall include, where appropriate, the following stages:
1.
Shredding of the waste or air removal or a combination of both
2.
Wetting and heating
3.
Decontamination
4.
Drying (when required by the waste disposal service)
Note: These stages may not be clearly separated in all equipment and the order of stages may vary. However, it facilitates the
evaluation of the efficacy and reproducibility of the process when the stages are clearly separated, especially when the
decontamination stage has clear start and end points and is conducted at a single temperature for a defined period.
4.2.1 Shredding waste and/or removing air
Shredding is an effective way of bringing moist heat into contact with all of the surfaces of the waste
materials. Moreover, shredding decreases the volume of the waste and renders it unrecognizable.
Shredders are designed to reduce the size of the items in the waste to particles of a specified size range,
which is chosen to allow the penetration of moist heat to the surfaces to be decontaminated. The
shredding of contaminated waste may, however, lead to the contamination of the working environment by
expelling aerosols and airborne particles. The design of the decontamination equipment shall include the
decontamination of the shredder during a routine cycle. The decontamination equipment shall also provide
Guideline Hospital Waste Decontamination Equipment
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the means to disinfect the shredder before maintenance or repair. The shredder’s filling funnel shall be
hermetically closed when the shredder is in operation. Any overpressure release vents shall be fitted with
adequate air filters. A manufacturer of decontamination equipment with a built-in shredder that claims that
the equipment is suitable to process injection needles is required to demonstrate that the size of the
injection needles will be reproducibly reduced to the size specified by the manufacturer to enable the
decontamination of the needles’ internal surfaces.
Shredding of the waste is not a prerequisite for the effective penetration of moist heat. Air removal allows
for the rapid and even penetration of moist heat in porous and hollow materials. Experience with the
sterilization of medical devices shows that a fractionated vacuum is almost always necessary in order to
remove air from hollow devices. The details of the pressures and stage times of the fractionated vacuum
are specified by the manufacturer. The validation of the process shall demonstrate the effective penetration
of moist heat. The test methods described in DIN 58949-3 use a standard hollow test item to demonstrate
the penetration of moist heat in hollow items.
Note: In equipment without a shredder, plastic materials may melt and form compact masses in which contamination is enclosed. This
contamination is consequently shielded from moist heat during the decontamination stage. Infectious agents inside the melted
plastics may not be inactivated. To prevent the release of these infectious agents, the decontaminated hospital waste must not be
shredded or compacted in a press container. The waste with intact enclosed contaminants is deemed to be decontaminated.
4.2.2 Wetting and heating
During this stage, the waste is wetted and heated. This stage is followed by the decontamination stage.
4.2.3 Decontamination
During the decontamination stage the temperature shall be maintained minimally at the decontamination
temperature, under saturated moist heat conditions.
4.2.4 Drying (when required)
During the final stage of the process, moisture is removed from the decontaminated materials to the level
specified by the waste disposal service.
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5
Equipment
5.1
General
a.
b.
The decontamination equipment shall fulfil all relevant European health and safety requirements.
The decontamination equipment is preferably designed to decontaminate all possible items
present in hospital waste, including lengths of tube, syringes, needles, suction bottles and growth
media from the laboratory. Where relevant for the decontamination process, the manufacturer shall
also specify the packaging of the waste.
All limitations in the use of the equipment, (for example, the composition of the waste, needles
yes/no, capacity, moisture content, packaging) shall be clearly stated by the manufacturer to the
potential purchaser.
The manufacturer shall provide the instructions for use, written in Dutch, in which the complete
decontamination procedure is described, from loading the equipment with waste, to the release of
the processed waste.
The manufacturer shall also describe the procedures to be followed in case of an emergency shut
down and/or equipment failure.
Where applicable, the manufacturer shall specify the safety measurers for the operators and the
working environment that are necessary during normal operation of the equipment and for
emergency access while hospital waste is present in the equipment.
The manufacturer shall provide schematic construction drawings, details of the process dynamics
(including process variables and the limits of the process parameters) and detailed installation
drawings (including a diagram of the locations of connectors and conduits of the external services,
such as electrical power, steam, water, pressurized air) to the user.
The manufacturer shall specify the required quality and quantity of the external services, (for
example, electrical power, steam, water, pressurized air), drains, climate control, ventilation, etc.
Such description shall include specifications for the connectors and fittings.
The manufacturer shall have the results from the type test and works test, as per Clause 7.1 and
7.2., available for the user. The results from these tests shall demonstrate that the
decontamination equipment is suitable to process the type of hospital waste specified by the
manufacturer.
After the installation of the decontamination equipment, an installation qualification and operational
qualification shall be performed as per Clause 7.3 and 7.4. When these qualifications are
performed by the manufacturer, the user shall be provided with the results.
After the successful OQ, it shall be demonstrated by performance qualification as per Clause 7.5.
that the decontamination equipment is suitable to effectively and reproducibly process the hospital
waste provided by the user. The user will write a plan for the PQ and effectuate it.
The decontamination equipment will only be released for routine use after successful completion of
PQ (see Clause 7.6).
The decontamination equipment shall be designed to prevent the uncontrolled emission of waste
materials, fumes, aerosols and vapours, for example, hermetically sealed, operating at
underpressure.
All materials and substances that are emitted from the decontamination equipment during or at the
end of the process shall be decontaminated. For example, air shall be filtered through a HEPA
filter before venting, waste water shall be collected and thermally decontaminated or returned into
the process.
The manufacturer shall specify the skills of the operators and, where necessary, offer training.
c.
d.
e.
f.
g.
h.
i.
j.
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5.2
Process
a. For disinfection, the decontamination time shall be at least 15 minutes at 100°C. The
microorganism to use in a microbiological qualification is Bacillus athropheus per DIN 58949-4
(formerly known as Bacillus subtilus var. globigii).
b. For sterilization, the decontamination time shall be at least 30 minutes at 121°C or equivalent, for
example, 7 minutes at 134°C, 20 minutes at 126°C, 2 minutes 143°C.
Note: When microbiological qualification is required to assess the efficacy of the process, the decontamination time should
correspond with the resistance of the biological indicator (NEN EN ISO 11138 parts 1 and 3).
c. The decontamination process shall be reproducible.
d. The stages of the decontamination process shall be univocally described. Preferably, only one
decontamination program is available. If more than one program is available, the purpose of each
program and the differences between the programs must be clear to the operator.
e. Decontamination equipment shall be provided with a self-decontamination cycle to decontaminate
all internal parts of the equipment that come in contact with the hospital waste and are therefore
contaminated during normal operation. In addition to an automated self-decontamination cycle, the
manufacturer shall provide the means to carry out a manually controlled self-disinfection cycle (for
example, in the event the equipment fails). The manufacturer shall provide instructions how to
perform the self-decontamination cycles. If the machine is equipped with a shredder, it shall be
also be decontaminated. The efficacy of the self decontamination process shall at least be equal to
a disinfection process for 15 minutes at 100°C under saturated moist heat conditions.
f. Manual adjustment of the process parameters in the controller should be avoided. If the
parameters can be manually adjusted, modification of process parameters shall only be possible
by authorized persons using a special key, code or tool.
g. At the request of the purchaser, the manufacturer will deposit the source code of the controller
software with a third party, such as a solicitor, bank, etc., so that the source code will be available
to the purchaser in case of bankruptcy. Details of the third party will be forwarded to the purchaser.
h. Decontamination equipment that uses a vacuum to enable the penetration of moist heat into
lengths of tube, needles, porous materials, etc., shall be constructed to allow the performance of
an air leakage test, a helix test per EN867-5, and the Bowie & Dick test per D6102.
i. Inspection hatches providing access to the internal parts of the decontamination equipment shall
be monitored to prevent the start of a cycle when one or more hatches are open, and to abort a
cycle when a hatch is opened during the cycle.
5.3
Monitoring, control, faults and maintenance
a. For the purpose of validation, means shall be provided to allow the performance of multi-point
temperature measurements in the hospital waste and the internal parts of the decontamination
equipment.
Note: Temperature measurements on the internal parts of the decontamination equipment are performed to demonstrate the
efficacy of the self-decontamination cycle on, for example, the loading funnel, shredder, transport screws and stirrers.
Decontamination equipment that operates at a pressure above atmospheric and/or uses a vacuum
for air removal shall be fitted with a connector for one or more pressure transducers.
Decontamination equipment provided with a shredder shall, for the purpose of validation and
monitoring, allow for the introduction of probes, data loggers, biological indicators, etc. into the flow
of shredded hospital waste after the shredder, for example, a hatch.
b. The decontamination equipment shall be fitted with two independent temperature measurement
systems. One system is used to control the process, the other is used to monitor and record
process parameters (see also NEN EN 285: 2006, Clause 6.2.). Both systems shall, under the
conditions of use and taking the ambient temperature, moisture, vibrations, etc. into account, not
deviate more than 1°C from the decontamination temperature.
Where applicable, the pressure shall be monitored and recorded. The pressure measurement
system shall, under the conditions of use and taking the ambient temperature, moisture, vibrations,
etc. into account, not deviate more than 4 kPa from the pressure of the decontamination
temperature.
The manufacturer shall state any other process variables that may affect the efficacy of the
decontamination process, such as the rotation speed of a transport screw, that affect the
decontamination time. These process variables shall be monitored and recorded. The
manufacturer shall provide a rationale for the accuracy of the additional measurement system(s).
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c.
d.
e.
f.
g.
h.
i.
j.
Where the recorded process parameters are presented as a graph, the resolution shall be
sufficient to allow the data on the chart to be read and interpreted without the need for additional
optical enhancement systems (such as magnifying glasses) or measuring tools (such as rulers).
The recorded process parameters shall be indicated to the operator during the process.
The decontamination equipment shall be fitted with a fault indication system. In the event of a fault,
the cycle shall be terminated and the cause indicated to the operator. The meaning of the
indications must be clear to the operator. Any text displayed or printed shall be in Dutch. Means
shall be provided to bring the process towards a safe situation to allow for the removal of the
waste. It must be presumed that the waste is still contaminated and shall be handled as such.
For safety reasons, it shall be possible to manually terminate the cycle. Termination of the cycle
shall be recorded by the process recorder. It must be presumed that the waste in the
decontamination equipment is still contaminated and shall be handled as such.
The manufacturer shall provide the means to safely remove the waste from the decontamination
equipment or reprocess the load in case of untimely termination of the cycle, either after a manual
cancellation of the cycle or as the result of a fault.
In double-door decontamination equipment, an interlock system shall prevent that both doors are
open at the same time and will ensure that that the unloading door can only be opened at the end
of a successfully completed process.
When required by the waste disposal service, the waste shall be dried to the specifications of the
waste disposal service.
The manufacturer shall provide a maintenance program and a maintenance protocol that
guarantee continuous operation according to specifications. At least the following actions must be
performed during maintenance:
• Check the state of the equipment; make sure all parts are free from corrosion, all indicators are
functioning, moving parts are running, etc.
• Check seals, conduits, fittings, etc. for leakage.
• Check the proper functioning of safety parts, e.g. overpressure release valve, door locks and
interlocks, temperature cut-outs, etc.
• Calibrate the sensors for process control, monitoring and recording.
• Where the decontamination equipment is provided with a built-in water treatment system or
where it is connected to an external water treatment system, the maintenance of the water
treatment system must be checked.
• Check, clean and replace filters.
The replacement or repair of parts during periodic maintenance may necessitate a requalification of the
decontamination equipment as per Clause 7.7. The manufacturer shall state the parts that necessitate
requalification upon replacement or repair.
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6
Validation
Validation is performed through physical measurements, where necessary complemented or replaced with
microbiological tests. Microbiological tests shall always be performed when it is not possible to measure
the critical process variables, as well as for decontamination equipment that does not operate with
saturated moist heat. Validation is performed to demonstrate that the type and quantity of hospital waste,
as specified by the manufacturer, can be effectively and reproducibly processed.
6.1
Type test
The manufacturer shall perform a series of tests that take into account the claims on the type and quantity
of hospital waste that the decontamination equipment is meant to process to demonstrate that the
specified performance is delivered.
Where the decontamination equipment is intended to process the full range of hospital waste without the
use of a shredder, hollow objects, such as lengths of tube and needles, are presumed to be those that are
the most difficult to process. The type test shall clearly demonstrate that these objects can be
decontaminated effectively.
The tests described in DIN 58949-3 shall be performed for both the disinfection and sterilization cycles. For
batch-process decontamination equipment, the procedure described in DIN 58949-3 shall be followed
without modification. For continuous process decontamination equipment, it may be necessary to modify
parts of the DIN procedure. The manufacturer shall clearly describe the test type procedure and provide a
rationale for each deviation from the standard procedure.
The type-test procedure and results shall be documented by the manufacturer. This document will also
provide the rationale for the selection of the works test.
The specifications for the measuring systems used during the type test are described in DIN 58949-3. The
requirements for biological indicators that are used in disinfection cycles are specified in DIN 58949-3 and
4. Parts 1 and 3 of NEN-EN-ISO 11138 specify the requirements for biological indicators that are used in
sterilization cycles.
All of the biological indicators shall be used in a process challenge device (PCD). The PCD shall be
designed to represent the object or part of an object that is the most difficult to decontaminate that may be
present in hospital waste.
DIN 58949-3 specifies the acceptance criteria of the thermometric measurements and biological indicator
tests in disinfectors.
For sterilizers, the measured temperatures shall fulfil the requirements stated in Richtlijnen Steriliseren en
Steriliteit; D6103b.
Note: When used in decontamination equipment that is provided with a transport screw, stirrer, impellor, etc., it may be necessary to
protect biological indicators, PCDs, data loggers, etc., from mechanical impact, for example, by means of steel baskets. This
protection must be sufficiently permeable for moist heat in order to ensure the efficacy of the process is not impaired.
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6.2
Works test
The manufacturer shall perform a series of tests to demonstrate that the decontamination equipment that is
shipped to a purchaser, or parts of the equipment that are assembled on site, meet the specifications. The
test program shall at least include the tests that proved to be the most critical in the type test. The test
procedure and acceptance criteria are identical to those used in the type test.
The manufacturer may decide to perform part of the works test at the user’s site during installation
qualification.
6.3
Installation qualification (IQ)
The purpose of IQ is to verify, at the user’s site, the specifications of the process, the equipment, the
operation and the generation of moist heat, as well as the quality and quantity of the services needed to
run the process.
The calibration status of all of the measuring systems for process control, monitoring, and recording,
including measuring systems for test purposes, must be established. The manufacturer shall write a
protocol for the IQ.
6.4
Operational qualification (OQ)
The purpose of OQ is to demonstrate that the decontamination equipment delivers, at the user’s site, the
decontamination process within the specified tolerances. The test program shall at least include the tests
that proved to be the most critical in the type test. The test procedure and acceptance criteria are identical
to those used in the type test.
6.5
Performance qualification (PQ)
Performance qualification enables the user to demonstrate that the site’s hospital waste can be effectively
and reproducibly decontaminated. The process variables shall be measured in representative locations in
the waste, and where applicable, in wastewater. The measurement procedure and acceptance criteria are
identical to those used in the type test.
Microbiological tests shall be performed where the continuous measurement of the temperature is not
possible during the process or where the efficacy of the process cannot be established by physical means.
The test procedure and acceptance criteria are identical to those used in the type test.
The following provisions must be taken into account during PQ:
• The packaging of the waste shall be identical to the packaging that is used in daily routine.
• The data from at least three consecutive successful decontamination cycles are needed to
establish the reproducibility of the process.
• The hospital waste that is used during PQ shall be quarantined until the results from the PQ
establish that the decontamination equipment reproducibly delivers an effective process within
the tolerances of the specifications.
6.6
Report
The data collected during the qualifications shall be documented and collated in a report. The documents
in the report may come from different sources (manufacturer, user, validation service). The report shall at
least contain the following information:
• Description of the decontamination equipment.
• Description of the processes.
• Description of the hospital waste.
• The data established for each process.
• Evaluation of the data established from measurements and tests, the acceptance criteria and
the standards used.
The user shall endorse the report by signing it and the decontamination equipment will be released for
routine use.
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6.7
Requalification
Requalification enables the user to establish that the decontamination equipment continues to deliver the
decontamination process within the specified tolerances after maintenance, repairs or modifications have
been carried out. The program of tests and measurements may be shorter than the program used for the
initial qualification. The user shall draft a requalification program that includes a rationale for the selected
tests and measurements. The program shall at least include the tests and measurements that produced
the poorest results during the last qualification.
Requalification shall be performed:
• At least once a year.
• After the replacement during maintenance or repair of parts that have a significant impact on
the performance of the decontamination equipment. The manufacturer shall provide the user
with a list of parts that require requalification.
• After modifications to the programmed processes, the packaging of the waste, the amount of
waste that is processed per batch or per period, and the type of waste that is offered for
decontamination. In general, requalification must be performed after each deviation from the
initial intended use.
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7
7.1
Routine monitoring and release of processed
waste
Process documentation
•
•
•
7.2
At the end of each decontamination cycle, the records are verified to establish that the process
parameters were within the specified tolerances. All pre-process activities, such as the
preconditioning of waste, that are necessary to guarantee the efficacy of the decontamination
process, are deemed to be part of the process. The parameters shall be recorded and verified.
For continuous decontamination processes, the user shall verify that, during the period that a
certain amount of waste was processed, the process parameters at the locations identified by
the manufacturer as the most critical were within the specified tolerances, and that the speed
of transport through the decontamination equipment was sufficiently low to ensure that the
waste was at the decontamination temperature for at least the intended decontamination time.
In the event that the processed waste cannot be clearly distinguished from non-processed
waste, chemical process indicators must be attached to the packaging of the waste before it is
loaded into the decontamination equipment. The use of such indicators is not necessary for
decontamination equipment that shreds the waste as part of the process.
Release of processed waste
•
•
The process documentation is collated into a release protocol. The user shall verify that the
process was within the specified tolerances and will endorse the protocol by signing it.
The user will ask the waste disposal service for the details of the information that must be
provided with the decontaminated waste. A photocopy of the release protocol and any other
requested documents will be handed over to the waste disposal service.
Guideline Hospital Waste Decontamination Equipment
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8
Literature
DIN 58949-3: Desinfektion - Dampf-Desinfektionsapparate - Teil 3: Prüfung auf Wirksamkeit [Disinfection Steam Disinfection Equipment - Part 3: Efficacy Testing], February 2004
DIN 58949-4: Desinfektion - Dampf-Desinfektionsapparate - Teil 4: Biologische Indikatoren zur Prüfung auf
Wirksamkeit [Disinfection - Steam Disinfection Equipment - Part 4: Biological indicators for efficacy tests],
October 2006
D6102: NEN, Steriliseren en Steriliteit, Bowie & Dick test (in Dutch), 1997
D6103b: NEN, Steriliseren en Steriliteit: Valideren van stoomsterilisatoren voor medische hulpmiddelen
[Sterilization and Sterility: Validation of steam sterilizers for medical devices], 2006
NEN-EN 285: Sterilization - Steam Sterilizers - Large Sterilizers, 2006
NEN-EN 556-1: Sterilization of Medical Devices - Requirements for Medical Devices to be Designated
‘STERILE’ - Part 1: Requirements for Terminally Sterilized Medical Devices, 2001
NEN-EN ISO 11138-1: Sterilization of Health Care Products - Biological Indicators - Part 1: General
Requirements, 2006
NEN-EN ISO 11138-3: Sterilization of Health Care Products - Biological Indicators - Part 3: Biological
Indicators for Moist Heat Sterilization Processes, 2006
NEN-EN ISO 11140-1: Sterilization of Health Care Products - Chemical Indicators - Part 1: General
Requirements, 2005
NEN-EN 867-5: Non-biological Systems for use in Sterilizers - Part 5: Specification for Indicator Systems
and Process Challenge Devices for use in Performance Testing for Small Sterilizers Type B and Type S,
2001
RIVM Survey 569/05 BMT/TPV/dBr/AvD/cvr, Decontaminatietechnieken specifiek ziekenhuisafval
[Decontamination techniques for specific hospital waste], A. W. van Drongelen, A. C. P. de Bruijn and G.
W .M. Peters-Volleberg, November 2005,
http://www.rivm.nl/bibliotheek/digitaaldepot/decon_spec_zkh_afval2006.pdf
Guideline Hospital Waste Decontamination Equipment
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Annex 1: Rationale for the decontamination process parameters
The key question is whether it is necessary to kill, with a high level of certainty, all micro-organisms in the
hospital waste (sterilization) or whether it is sufficient to reduce the number of pathogenic micro-organisms
to a level that ensures the safety of the persons handling the waste (disinfection). Sterilization has the
advantage of a defined end point; the chance of finding a living micro-organism is less than one in a
million. Starting with the high estimated bioburden in hospital waste of 1018 micro-organisms per item, a
sterilization process per European Pharmacopoeia with twice the standard sterilization time (121°C for 30
minutes), should be sufficient to render the waste sterile. Sterilization in the laboratory destruction
autoclaves may prove to be a feasible solution for many hospitals. Due to the limited capacity of such
autoclaves, the amount of hospital waste should be limited by strict separation of the waste at the source.
Disinfection requires a definition of the infectious micro-organisms that have to be inactivated before the
hospital waste can be safely transported to the regional incinerator (AVI). Literature provides lists of microorganisms that are known to be dangerous and should be eliminated before the hospital waste is
transported from the premises. The lists contain a large number of viruses. Viruses are not heat resistant
and are of no consequence for the choice of the process parameters.
Hospital waste containing prions is not dangerous. Prions are dangerous for humans, but according to the
current state of knowledge, only if transmission occurs through the eye or the brain. These transmission
routes are unlikely to occur while handling waste. In view of their extremely high resistance to sterilization
processes, inactivation by incineration is the preferred method.
Clostridium botulinum is a dangerous micro-organism that can cause serious illness and is highly resistant
to moist heat. Infection from hospital waste is, however, unlikely since the route of transmission is oral [1].
The micro-organisms listed by WIP in its guideline on waste management [2] are also mentioned in
categories A, B, and C of the German Robert Koch Institute (RKI) [3]. Bacillus anthracis is, in relation to the
decontamination of hospital waste, the most resistant micro-organism.
Contrary to sterilization, it is not easy to define an effective disinfection process. The descriptions of the
waste decontamination equipment that is listed by RKI indicate that it can take a considerable amount of
time for the waste materials to heat up during the decontamination process. RKI points out that users must
be aware of the presence of solid masses that are difficult for heat to penetrate, as well as of large
containers filled with liquids. In waste decontamination equipment that shreds waste before it is exposed to
the actual decontamination stage of the process, a disinfection time of 15 minutes at 100°C is deemed to
be sufficient, whereas in general-purpose steam disinfectors, a disinfection time of 30 minutes is
recommend to compensate for the poor heat penetration [3]. The process parameters that were first
mentioned may be regarded as the reference values to which the waste must effectively be exposed,
disregarding the heat-up period. Whether specific waste decontamination equipment delivers an effective
process must be established by tests and measurements.
RKI uses the German standard DIN 58949-3 [4] for the admission criteria. This standard describes the
requirements and methods for the validation of waste decontamination equipment. The methods include
microbiological tests in combination with porous materials (textiles, bandages, wound dressings, surgical
drapes, etc.) and hollow objects (injection needles, lengths of tubes, etc.), as well as thermometric
measurements. The micro-organism used in the tests is Bacillus subtilis, per DIN 58949-4 [5]. This microorganism is present everywhere in the environment and is of no consequence for the decontamination of
hospital waste. It is a much used test organism for decontamination processes and is more resistant to
moist heat than Bacillus anthracis. Sykes [6] found that, at 100°C, the inactivation time for B. subtilis is a
multiple of the inactivation time for B. anthracis. B. subtilis seems to be an acceptable test organism; its
high resistance provides an additional safety margin. Due to the large difference in the inactivation time for
B. anthracis and B. subtilis, decontamination equipment that is capable of inactivating a challenge of B.
subtilis will, with a high level of certainty, be able to inactivate B. anthracis.
The risk of micro-organisms growing from the decontaminated waste is negligible. The efficacy of the
decontamination process is sufficient to inactivate resistant micro-organisms, diminishing the chance of
survivors. Drying the waste during the process further impoverishes the conditions for growth.
Guideline Hospital Waste Decontamination Equipment
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The data on inactivation specified above are only valid for decontamination with saturated moist heat. For
dry heat, insufficient data are available from literature to state the process parameters that will produce an
efficacy equal to the moist heat disinfection at 100°C for 15 minutes. Sterilization with dry heat is possible
using a standard process with a double exposure time, for example, 60 minutes at 180°C. Dry heat
decontamination processes are, however, outside the scope of this guideline.
Literature:
1. Chin JE, Control of Communicable Diseases Manual, edn 17, vol. pp. 70–75 AMERICAN PUBLIC
HEALTH ASSOCIATION, 2000/01, ISDN 0-87-553242-X
2. Infectiepreventie bij afvalverwijdering vanuit instellingen voor gezondheidszorg [Infection
prevention during sanitation for health care facilities], Dutch Working Group Infection Prevention
(WIP), June 2004,
http://www.wip.nl/free_content/Richtlijnen/11Afval.pdf
3. Liste der vom Robert Koch-Institut geprüften und anerkannten Desinfektionsmittel und –verfahren
[Robert-Koch-Institute list of tested and approved disinfection agents and methods], Robert KochInstitut, edn 14, 31 May 2002
http://www.rki.de/cln_011/nn_226928/DE/Content/Infekt/Krankenhaushygiene/Desinfektionsmittel/
Desinfektionsmittelliste,templateId=raw,property=publicationFile.pdf/
4. DIN 58949-3: Desinfektion - Dampf-Desinfektionsapparate - Teil 3: Prüfung auf Wirksamkeit
[Disinfection - Steam Disinfection Equipment - Part 3: Efficacy Testing], February 2004
5. DIN 58949-4: Desinfektion - Dampf-Desinfektionsapparate - Teil 4: Biologische Indikatoren zur
Prüfung auf Wirksamkeit [Disinfection - Steam Disinfection Equipment - Part 4: Biological
Indicators for Efficacy Tests], October 2006
6. Sykes G, Disinfection and Sterilization (Spon Ltd., London, 1958), p. 95.
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Annex 2: Correlation between temperature and pressure in saturated steam
There is a mathematical correlation between the temperature and the pressure1 in saturated steam. The
temperature and pressure measurements are used in the below equation to determine whether the steam
is saturated. In saturated steam, the calculated temperature matches the measured temperature.
T = A + B (lnP + C)-1
where:
T is the theoretical steam temperature, in Kelvin;
P is the measured pressure, in Mega Pascal;
A is 42,677 6 K;
B is –3 892,70 K;
C is –9,486 54
1
Irvine TH. F., Liley, P. E., Steam and Gas tables with computer equations (Academic Press, 1984).
Guideline Hospital Waste Decontamination Equipment
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Annex 3: Validation – Schematic representation
In order to interpret the validation, it is important to understand the sequence of the type test, works test,
installation qualification, operational qualification, performance qualification and requalification, as
described in this guideline.
Requalification
Routine monitoring, change control
Specified user requirements
Type and amount of waste, monitoring /
recording, routine monitoring, validation,
etc.
Related to
Performance Qualification (PQ )
Validation of actual loads, establish
reproducibility
User
User / M anufacturer
Specified function requirements
programs, air removal, dryness, air
leakage, fault handling, etc.
Installation specifications
Services, e.g. steam, water, air, drain,
power etc., noise, ambience.
Related to
Related to
Operational Qualification (OQ)
Thermometric tests, air-leakage test,
dryness test, moist-heat-penetration test.
Installation Qualification (IQ)
Check specifications, drawing,
documentation etc.
M anufacturer / User
M anufacturer
Design specifications
Related to
W aste disposal service
Additional requirements and conditions
Design Qualification (DQ)
Type test / W orks test
M anufacturing
Quality assurance of production
through certified quality
management system
Guideline Hospital Waste Decontamination Equipment
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Annex 4: Persons involved in drawing up the guideline
This document was drafted by:
Mr A. de Bruijn (National Institute for Public Health and the Environment: Medical Technology Section)
Mr A. van Drongelen (National Institute for Public Health and the Environment: Medical Technology
Section).
The following persons are acknowledged for their valuable input during the drafting process:
Mr G. Bakker (Darwin Business Partners)
Ms Th. Daha (Dutch Working Group Infection Prevention, WIP)
Mr J. van Doornmalen (Bureau Veritas)
Mr J. van Hasselt (Van Gansewinkel)
Mr R. Heijlijgers (Bureau Veritas)
Mr L. Lamphen (University Medical Centre Utrecht)
Mr L. Maas (University Hospital Maastricht)
Mr P. Maris (Sanamij)
Mr T. Ritmeijer (Van Vliet Medical Supplies)
Ms A. Teuns (Van Gansewinkel)
Mr G. van Vliet (Van Vliet Medical Supplies)
Mr C. Wagenaar (Nido Recycling Techniek)
Mr E. Wigmore (Nido Recycling Techniek).
Mr R. van Zwieten (Ministry of Housing, Spatial Planning and the Environment)
Full consensus on all of the requirements described in this document was not achieved. When asked, the
contributors may express an opinion different from the information in this document.
This document is a translation of the Dutch guideline Richtlijn decontaminatie-apparatuur ziekenhuisafval,
dated December 2006.
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