Flammability of fridge insulation
foam produced with a hydrocarbon
blowing agent
Version 1.0
December 2012
Flammability of fridge insulation foam produced with a hydrocarbon blowing agent
LIT 7627
1
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Flammability of fridge insulation foam produced with a hydrocarbon blowing agent
LIT 7627
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Contents
1
Summary ............................................................................................................. 4
2
Introduction .......................................................................................................... 4
3
Methodology ........................................................................................................ 5
3.1
Collection of samples .................................................................................... 5
3.2
Laboratory tests ............................................................................................ 7
4
Summary of Results ............................................................................................ 9
5
Conclusions ....................................................................................................... 10
6
5.1
Coding, classification and consignment of waste ........................................ 10
5.2
Safe handling, storage and treatment ......................................................... 11
5.3
Other wastes ............................................................................................... 12
Acknowledgments.............................................................................................. 12
Appendix 1 – Information recorded from sampled cooling appliancse ..................... 13
Appendix 2 – Results of burn rate tests for fridge foam samples ............................. 14
Flammability of fridge insulation foam produced with a hydrocarbon blowing agent
LIT 7627
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1 Summary
The aim of this study was to test the flammability of fridge1 insulation foam produced
using a hydrocarbon blowing agent in order to assess potential implications for the
prevention of accidents and incidents from the storage and treatment of waste
fridges. This report would also be used to clarify and review appropriate classification
and coding under the Duty of Care and Hazardous Waste Regulations2.
The study found that all tested foam samples should be considered “highly
flammable” under European Test Method A.10 Flammability (Solids)3 and concludes
that all fridge insulation foam produced using a hydrocarbon blowing agent should be
classified as hazardous waste, unless tested and demonstrated otherwise.
The results of the study will be used to:
-
Identify options for minimising or preventing accidents and incidents
-
Ensure that fridges containing hydrocarbon blown foams are sent to
appropriate permitted treatment facilities for storage and further treatment
-
Inform the classification/consignment of waste foam produced by fridge
treatment activities; ensuring that a consistent approach is taken
2 Introduction
Modern fridges often contain insulating foam that is blown with hydrocarbon (HC)
blowing agents, usually cyclopentane but may also include n-pentane and i-pentane,
collectively referred to in this report as “pentane”. These hydrocarbon blowing agents
have replaced the use of chlorofluorocarbon (CFC) and Hydrochlorofluorocarbon
(HCFC)
blowing
agents
(ozone
depleting
substances
(ODS))
and
Hydrofluorocarbons (HFC) blowing agents (gases with high global warming potential
(GWP)). HC blowing agents are not ODS and do not have a high GWP but pose
greater fire risk due to their high flammability.
Permitted fridge treatment facilities accept fridges (those containing
CFC/HCFC/HFC/HC refrigerants and blowing agents) and process them to remove
the oil and capture the refrigerant from the cooling circuit. Once this is done, in
1
The term “fridge” is used in this report to refer to cooling appliances that contain insulating foam;
including fridges, fridge-freezers, freezers, chest-freezers and refrigerated displays.
2
See http://www.environment-agency.gov.uk/business/topics/waste/40047.aspx and
http://www.environment-agency.gov.uk/business/topics/waste/32180.aspx for further information.
3
Test method specified in Annex V of Directive 67/548/EEC and Appendix C of Environment Agency
Technical Guidance WM2 for the assessment of the flammability of a solid substance.
Flammability of fridge insulation foam produced with a hydrocarbon blowing agent
LIT 7627
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accordance with the WEEE Directive and associated Defra BATRRT guidance4, the
degassed CFC, HCFC and HFC fridge carcasses must be treated in dedicated plant,
which will ensure that the blowing agent is collected and sent for destruction (e.g.
incineration).
The WEEE Directive and Defra BATRRT guidance do not explicitly require the
collection and destruction of hydrocarbon blowing agents; however appliances
containing foam produced with these blowing agents must be treated in “intrinsically
safe” plant. In addition to being processed in dedicated fridge plants, a number of
operators currently co-process degassed hydrocarbon fridges in scrap metal
shredders, whilst others process them in generic waste shredders.
There has been uncertainty regarding the correct classification of degassed
hydrocarbon fridges (containing foam with a hydrocarbon blowing agent) under Duty
of Care/Hazardous Waste Regulations and they have often been classified and
transferred as non-hazardous wastes (e.g. under European Waste Codes 16 02 14
(discarded equipment other than those mentioned in 16 02 09 to 16 02 13) or 20 01
36 (discarded electrical and electronic equipment other than those mentioned in 20
01 21, 20 01 23 and 20 01 35)).
Pentane blowing agents that are used in the insulating foam of fridges have the R11
(highly flammable) risk phrase (note: term not to be confused with “R11” CFC
refrigerant). The pentane is entrained within the foam and therefore the material
should be assessed for flammability as a solid in accordance with Test Method A.10
Flammability (Solids). If the foam is assessed as being hazardous (i.e. under the
R11 risk phrase) then it would be assigned the H3A (highly flammable) hazardous
property and appliances that contain it as a component would be classified
hazardous waste under European Waste Code 16 02 13* (discarded equipment
containing hazardous components other than those mentioned in 16 02 09 to 16 02
12) or 20 01 35* (discarded electrical and electronic equipment other than those
mentioned in 20 01 21 and 20 01 23 containing hazardous components).
3 Methodology
3.1
Collection of samples
The fridge appliances used to obtain the samples of insulation foam were provided
by European Metal Recycling Ltd at their Darlaston facility. A sample of fridge foam
was taken from 20 fridge appliances that had been identified as containing a
hydrocarbon (pentane) blowing agent. Each foam sample was cut from the side
panel of the appliance using a reciprocating saw and cut to the following
approximate dimensions: 200mm x 400mm (Figure 1). The height/depth of the
4
http://archive.defra.gov.uk/environment/waste/producer/electrical/documents/weee-batrrtguidance.pdf
Flammability of fridge insulation foam produced with a hydrocarbon blowing agent
LIT 7627
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sample depended upon the thickness of the foam panel, which was generally
between 40-100mm. Once cut, each sample was numbered, recorded and doublebagged. For each sample, the following information was also obtained from the
corresponding appliance, where available:

Blowing agent type

Manufacturer and model

Fridge type and capacity/volume

Refrigerant type and charge
The information obtained from each appliance is summarised in Appendix 1.
Figure 1 Cutting of foam panel and collection of fridge information
The blowing agent type was recorded from markings stamped on the exterior of the
appliance and the other information (fridge type, refrigerant charge etc) was taken
from the appliance name plate (e.g. as shown in Figure 2).
Figure 2 Blowing agent marking and appliance name plate
Flammability of fridge insulation foam produced with a hydrocarbon blowing agent
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3.2
Laboratory tests
The samples of fridge insulation foam were tested by the Environment Agency
National Laboratory Service (NLS), Nottingham, following Test Method A.10
Flammability (Solids). The blowing agent contained in each of the samples was
analysed and confirmed using gas chromatography mass-spectrometry (GC MS).
Figure 3 Double-bagged samples of foam in laboratory
Following the test method, test samples were cut as unbroken strips from the foam
panels to the following dimensions: 250mm long, 20mm wide by 10mm high. The
test samples were cut to the required shape using a hacksaw blade and an
aluminium cutting guide (shown in Figure 4).
Figure 4 Cutting of test sample from foam panel
Test method A.10 requires all substances to be subjected to a preliminary screening
test, prior to the burning rate test. All samples satisfied the requirements of the
Flammability of fridge insulation foam produced with a hydrocarbon blowing agent
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preliminary screening test (in terms of substance ignition and propagation of
combustion) and were therefore passed on to the burning rate test.
For the burning rate tests, the samples of foam were placed on non-combustible
plates inside a fume cupboard and lit at one end using a gas burner. The
propagation of the flame along the length of the sample was recorded using a digital
stopwatch.
Test method A.10 states that a substance should be considered highly flammable
when the burning rate over 100mm of any test sample is less than 45 seconds. The
method requires the rate of burning over 100mm of the sample to be measured after
the flame has burned an initial distance of 80mm. These two distances were marked
out on the non-combustible plates positioned below the test samples so that the
burning rate of the flame over the required 100mm could be timed using the
stopwatch (as shown in Figure 5).
1) Ignition of test sample
Markers
2) Flame propagation reaches
80mm marker, stopwatch started
80mm
3) Flame propagation reaches
180mm marker, stopwatch stopped
180mm
Figure 5 Trial run of burning rate test
The test method requires that the test is performed six times unless a positive result
is observed earlier. All test samples provided a positive result, however the burn rate
test was repeated on three test samples cut from each panel (i.e. 60 tests were
carried out in total, with 3 test samples taken from each of the 20 foam panels).
Flammability of fridge insulation foam produced with a hydrocarbon blowing agent
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4 Summary of Results
The results of the burn rate tests and GC MS analysis carried out on the samples cut
from the fridge insulation panels are tabulated in Appendix 2.
Blowing agent type
The GC MS analysis of the blowing agent(s) contained in the foam panels confirmed
that each panel contained a hydrocarbon blowing agent, as had been marked on the
exterior of the appliances (see Appendix 1). The results also confirmed that
cyclopentane was the principal hydrocarbon blowing agent used in the foam panels.
However, 9 foam panels also contained iso-pentane as a minor constituent (with
cyclopentane identified as the main constituent), and 2 panels contained iso-pentane
as the main constituent.
Burning rates
All foam samples burned the required distance (100mm) in a time under 20 seconds.
The slowest burn rate recorded was 19.3 seconds (test sample 3, fridge 1) and the
fastest recorded was 2.8 seconds (test sample 1, fridge 8). The average burning rate
time across all 60 samples was 9.4 seconds.
The fastest and slowest burning samples both contained cyclopentane blowing
agent. The type of hydrocarbon blowing agent did not appear to have a significant
effect on the burning rate of the foam samples, with the average burning rate
between the 3 types (i.e. those containing a) cyclopentane, b) cyclopentane and isopentane (as minor constituent) and c) iso-pentane (as main constituent)) being 9.7,
9.3 and 9.2 seconds respectively. Therefore, variability in burning rate between
samples was possibly due to variability in hydrocarbon blowing agent content
(quantity), rather than type.
Test method A.10 states that a substance should be considered as highly flammable
when the time of burning in any tests carried out according to the test procedure is
less than 45 seconds. As illustrated in Figure 6, the burning times recorded for all 60
test samples were significantly less than 45 seconds (all were below 20 seconds)
and therefore all tested material were considered “highly flammable” in accordance
with the test procedure.
Flammability of fridge insulation foam produced with a hydrocarbon blowing agent
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60.0
50.0
Burn rate (seconds)
45 second threshold specified by test method A.10
40.0
30.0
20.0
10.0
0.0
Fridge number
Figure 6 Average burn times of foam panel samples taken from each fridge
5 Conclusions
As stated in section 4, based upon the test data obtained from this investigation, it
was concluded that all fridge panels tested should be considered as highly
flammable solid materials. As a result of this, we believe that all fridge insulation
foam produced using a hydrocarbon blowing agent should be considered highly
flammable, unless tested and demonstrated otherwise.
This conclusion has the following potential implications:
5.1
Coding, classification and consignment of waste
When assessing waste electrical equipment, such as fridges, it is the presence or
absence of hazardous components that determines if they are classed as hazardous
waste or not. Insulation foam that has been blown with a hydrocarbon blowing agent
(pentane) has been demonstrated to posses the hazardous property H3A (highly
flammable). This means it is a hazardous component and would, amongst other
components, make a fridge a hazardous waste.
On the basis of this, degassed fridges (appliances that have had the
refrigerant/compressor removed) that contain insulation foam produced with a
hydrocarbon blowing agent should be classified and consigned under one of the
following hazardous waste codes: 16 02 13* or 20 01 35*. Similarly, foam panels
Flammability of fridge insulation foam produced with a hydrocarbon blowing agent
LIT 7627
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mechanically cut and removed from fridges that contain a hydrocarbon blowing
agent should be classified and consigned under the 19 12 11* waste code.
Waste residues resulting from waste shredding or fragmentising activities that coprocess degassed fridge carcasses that contain insulation foam produced with a
hydrocarbon blowing agent should be classified as hazardous waste under code 19
02 04* (premixed wastes composed of at least one hazardous waste), unless it can
be demonstrated that the hydrocarbon blowing agent has been removed from the
foam by the shredding process5.
The requirements of the revised Waste Framework Directive (2008/98/EC),
specifically regarding the ban on the mixing of hazardous wastes (Article 18), will
apply to the management of these hazardous wastes.
5.2
Safe handling, storage and treatment
In Defra’s WEEE BATRRT guidance, it is stated that appliances containing
hydrocarbons must be processed in intrinsically safe equipment. Many pentane
blown fridges are currently processed in dedicated fridge plant where the foam is
separated, milled and heated to release and collect the blowing agent. Typically, this
is done under a nitrogen inerted atmosphere to meet the BATRRT criteria. However,
not all dedicated treatment plant are currently inerted and it is unclear how these
plants will operate with the changing proportions of ODS to pentane fridges (i.e. as
the proportion of fridges that contain pentane increases).
A small number of other operators currently co-process pentane blown fridges in
light iron shredders, which could potentially pose a risk if the shredding process
releases the pentane (although we understand that the air dilution provided might be
adequate to keep gas concentration below the explosive limit) or if a spark ignites
the foam material. We also understand that some operators are using general waste
shredders to process pentane fridges, which may cause greater safety concerns.
We are currently in discussions with the HSE to confirm the definition of “intrinsically
safe equipment”.
It must be ensured that at sites accepting or producing wastes consisting of or
containing hydrocarbon-blown fridge foam appropriate measures are provided for
their safe storage and handling to prevent fire initiation and escalation/propagation
(i.e. appropriate measures for waste separation/segregation (e.g. fire breaks/walls)
and the prevention of flammable atmospheres).
5
See Environment Agency guidance Classifying and coding wastes from physico-chemical treatment
facilities HWR06 for further information on the principles of treating and classifying hazardous wastes,
available from http://www.environment-agency.gov.uk/business/topics/waste/104765.aspx
Flammability of fridge insulation foam produced with a hydrocarbon blowing agent
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5.3
Other wastes
This investigation has focussed on the flammability of hydrocarbon-blown fridge
insulation foams. However, the same potential issues/implications may apply to the
classification/consignment, storage and treatment of other similar waste foam
materials that contain a hydrocarbon blowing agent (e.g. building insulation foam,
insulation foam contained in other types of appliances, furniture foam and packaging
materials).
Under the requirements of the Duty of Care and Hazardous Waste Regulations, it is
the responsibility of the waste producer to ensure that all wastes are described and
classified correctly, taking into account any relevant hazardous properties.
6 Acknowledgments
We wish to acknowledge the help provided by:

European Metal Recycling, Darlaston - for providing and assisting with the
collection of the fridge foam samples.

The National Laboratory Service, Nottingham - for assisting in the design and
implementation of the testing methodology.
For further information, please contact National Operations, Waste Technical
Services.
Flammability of fridge insulation foam produced with a hydrocarbon blowing agent
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Appendix 1 – Information recorded from sampled cooling appliancse
Fridge
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Manufacturer/model
Electrolux / ERN2821
BEKO / TLDA5215
Bosch / KSV24214B/02
LEC / EL550BW
Unidentified
Bosch / unidentified
Hotpoint / RLA18G
LEC / T350CW
Electrolux / ER6641T
Whirpool / RPT531-1/H
Scandinova
Indesit / RGV1142UK
Unidentified
Whirlpool / RE128
Proline PLF140W
Hotpoint
Kyoto KU96FF
Hotpoint / FFA71P
BEKO / T3DA524FW
Hotpoint / FZA50P
Description
Fridge freezer
Fridge (large)
Fridge freezer
Fridge
Fridge
Fridge freezer
Fridge freezer
Fridge freezer
Fridge
Fridge freezer
Fridge
Fridge
Freezer
Fridge
Fridge
Freezer
Freezer
Fridge freezer
Freezer
Freezer
Type/capacity
Type 2 / 283l
Type 2 / 260l
Type 2 / 222l
Type 1 / 13l
Type 1
Type 2 / 315l
Type 2 / 353l
Type 2 / 190l
Type 1 / 159l
Type 2 / 189l
Type 2
Type 1 / 91l
Type 1
Type 1 / 118l
Type 1 / 110l
Type 2
Type 2 / 260l
Type 2 / 292l
Type 2 / 197l
Type 2 175l
Blowing agent mark on
appliance
Pentane
C-Pentane/ I-pentane
n-Pentane
Pentane
Pentane
Pentane
Pentane
Pentane
Pentane
C-Pentane
Cyclopentane
Cyclo / Iso pentane
Cyclopentane
Cyclopentane
Cyclopentane
Pentane
Pentane
Pentane
C-pentane I-Pentane
Pentane
Refrigerant type
& charge
R600A 80g
R600A 28g
R600A 56g
R600A 20g
Unidentified *
R600A *
R600A 30g
R134A 70g
R134A 55g
R600A 52g
R134A *
R134A 60g
R600A *
R600A 30g
R600A 25g
R600A *
R600A 60g
R600A 43g
R600A 44g
R600A 37g
* Charge (quantity of refrigerant in cooling circuit) not stated on appliance
Flammability of fridge insulation foam produced with a hydrocarbon blowing agent
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Appendix 2 – Results of burn rate tests for fridge foam samples
Fridge
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Burn times (100mm in secs)
Sample 1 Sample 2 Sample 3
7.5
12.8
19.3
10.7
9.8
9.7
12.6
16.0
13.6
7.1
11.7
8.9
15.7
7.9
8.0
6.2
11.7
5.8
8.2
12.4
15.1
2.8
5.5
6.7
10.9
4.8
10.7
4.3
4.4
4.1
10.1
5.0
9.1
9.8
8.2
5.4
5
13.5
10.4
9.8
15.9
12.8
5
8.4
3.9
4.4
10.2
8.4
11.3
16.1
15.8
10.3
12.1
9.8
9.2
9.3
7.6
8
9.2
7.7
Average
Average
burn time
13.2
10.1
14.1
9.2
10.5
7.9
11.9
5.0
8.8
4.3
8.1
7.8
9.6
12.8
5.8
7.7
14.4
10.7
8.7
8.3
9.4
Identified blowing agent(s) from GC analysis
Cyclopentane
Major constituent cyclopentane, minor iso-pentane
Major constituent cyclopentane, minor iso-pentane
Cyclopentane
Major constituent iso-pentane, minor pentane
Major constituent iso-pentane, minor pentane
Major constituent cyclopentane, minor iso-pentane
Cyclopentane
Cyclopentane
Major constituent cyclopentane, minor iso-pentane
Cyclopentane
Major constituent cyclopentane, minor iso-pentane
Cyclopentane
Cyclopentane
Cyclopentane
Major constituent cyclopentane, minor iso-pentane
Cyclopentane
Major constituent cyclopentane, minor iso-pentane
Major constituent cyclopentane, minor iso-pentane
Major constituent cyclopentane, minor iso-pentane
Flammability of fridge insulation foam produced with a hydrocarbon blowing agent
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