Plastic Tealight Cups

Plastic Tealight Cups
A JOURNEY THROUGH TIME
3rd World Candle Congress
Disney World – Orlando Florida
July 8, 2010
Bob Moss – SEA Ltd.
- OVERVIEW • Introduction of plastic tealight cups – a trip back in time.
• Observed failures – what types of failures are occurring and
what is the chronology.
• Industry reactions – how did the ASTM task group react and
make attempts to address the issues?
• Designs of experiments – what were these and what were the
results?
• Adopted standards – what test requirements were developed
and implemented?
• Refinement – how do we improve upon the test requirements to
reduce the risk of failure?
• Conclusions – what have we learned?
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- Let Us Begin Our Journey • Do you remember when…..
• When the movie Back to The Future
was released into theaters?
• 1985
• How about when Cheers was the
#1 TV show in the USA?
• 1990
- According to Sources • The arrival of clear plastic tealight cups is not
well documented. Sources indicate that these
items entered the market place between the
mid 1980’s and early 1990’s.
• The first patent specifically for the design of
clear plastic tealight cups was issued in June
of 2001 to J Jeneral.
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- The year is 2000 • This is where our story really begins.
• Begin to see documented problems with
clear plastic tealight cups.
• Problems observed include higher
flames and involvement of the tealight
cup either melting or burning.
The problems…
&
Flame impingement causing
melting
Heat melts hole
through the
bottom
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- Early Actions of ASTM F15.45 •
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Task group is data driven meaning before we take specific action we
need to agree there is a problem and then also agree on an approach
to address that problem.
Much discussion as to what to do between 2000 and 2002.
Some on committee felt a need for specific flammability requirements
for tealight cups in the standard.
Some felt there should be language in the standard about melting the
sidewall or melting a hole in the container.
Still others felt that the fragrance in the tealight candle might be
interacting with the cup in some way either causing the cup to be more
brittle or more flammable.
Others felt end of useful life requirements would capture failures.
ASTM is a consensus process – at that time the consensus was that
these issues occurred at end of life and that the end of life
requirements in the standard would address this problem
ASTM PS59-02 becomes a standard.
- Recalls Begin • In December of 2002 two recalls of clear plastic
tealight cups Atico and Home Interiors – one for the
wick not being properly set inside the tealight which
could cause the plastic to melt, the other for flames
of the tealight candle flaring up causing melting the
holder.
• November of 2003 Polardreams International recalls
plastic tealights due to “larger – than – normal” flame
heights as the candle burns to end of life.
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- Recalls Continue • April 2005 – Southern Living at Home high flame – due to contamination in
one production lot.
• November 2005 – Target – candles can
burn with high flames and melts plastic.
• March 2006 – Big Lots – candles can
burn with high flames melts plastic.
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- November 2006 • Claim – plastic tealight cups catching fire and
melting.
• Manufacturer had specified polycarbonate
cups from offshore supplier; however, the
performance of the cups indicated otherwise.
• Testing is initiated – use test of 90 candles –
burn testing in accordance with ASTM F2417.
• Result of testing - no fires occurred with the
plastic only melting.
Tealight cup melted allowing wax to escape
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- FTIR Analysis of Cups -
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- Recalls Continue -
• January 2007 – Sally Foster – tealight
cup can melt or ignite.
• February 2008 – Christmas Tree Shops
– tealight cup can melt or ignite.
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Proposed Flammability test to
Candle Fire Safety Standard
• In 2007 a it was proposed that a modified
version of ASTM D3801 be used to evaluate
flammability of tealight cups.
• Also proposed that stringent performance
requirements for cups – no ignition, this
would hopefully eliminate the use of
flammable materials as cups.
Example of Test
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Unacceptable Result
- 2007 / Things Begin to Heat Up • Task Group gets input from polymer manufactures
and tealight cup manufacturers.
• Group begins to design experiments to evaluate
plastic tealight cup flammability using virgin cups and
also design an in use aggressive test.
• Experiments also designed for fragrance
compatibility.
• Flammability of virgin cups was initially determined to
be most important issue in the opinion of the group.
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- Design of Experiment for
Flammability of Cups • Modeled after ASTM D3801 but with a variation in the
ignition source and how the material is oriented.
• 10 individual, identical cups to be used in each test.
• Cups were to be evaluated for flammability in both
vertical and horizontal position.
• Multiple types of materials that could be molded into
cups were to be tested – i.e. various polymers.
• There were to be multiple Labs to conduct testing.
• Samples were to be submitted blind to the labs so they
did not know what type of polymer they were testing.
- Initial Testing in 2007 • Materials tested were clear polymers that might be
used in tealight cup applications these included
various grades of polycarbonate, various polymer
alloys, polypropylene, and polystyrene.
• Cups were tested in both the vertical position and
also in the “in use” or horizontal position.
• The test was made by impinging the flame from a
butane lighter on to the lip of the cup for two 10
seconds exposures.
• The cups were evaluated for “after flaming” – how
long does the material continue to burn once the
ignition source is removed.
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- Initial Testing in 2007 Continued • Two companies manufactured materials for
testing.
• Four laboratories were involved in the round
robin testing – samples submitted as a “blind”
test.
• Cups were tested as virgin material – no
candles were introduced to the cups.
• Test data was evaluated to determine if it
was sensitive enough to get unacceptable
material off the market.
Example of Test
in Vertical Position
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Example of Test
“in use” Position
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- Results of Initial Flammability Testing • Cups made of polystyrene and polypropylene
continued to burn and had to be manually
extinguished.
• The grades of polycarbonate cups that were
tested tended to extinguish quickly.
• Testing revealed unexpected result with one
polymer showing that if a material was
contaminated with a flammable substance the
test may be sensitive enough to detect it.
- January of 2008 • The 2007 test protocol was repeated but
without the polystyrene or polypropylene
materials, i.e. only the polycarbonate and
polymer alloys were utilized in this test.
• Sample cups were tested both in vertical and
in normal use orientations.
• Same testing labs as before conducted the
tests.
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- January of 2008 • Same manufacturers as before supplied the
cups.
• In general cups that were tested in normal
use position extinguished relatively quicker
then cups in vertical position.
• Because of longer burn times it was generally
felt that the cups tested in a vertical position
gave a greater sensitivity to the test.
- Additional Information Being Gathered • Several members of the ASTM Candle Fire Safety Task
Group Evaluated plastic tealight cups with raw
fragrance oils showed that some interactions can occur
and that this needed to be studied further to fully
understand what the reactions were. Mostly observed
cracking of plastic but no confirmed changes in
flammability characteristics .
• Forced flashover testing was conducted with
polycarbonate clear plastic tealight cups test resulted in
the cup melting flat but not contribute to overall fire.
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- Developing a Requirement in the Standard • In 2008 the ASTM Candle Fire Safety Task Group
developed the following requirements based on the
testing that was completed.
• 10 specimens of new unused tealight cups are
tested.
• Cups are to be tested in the vertical position.
• Cups exposed two times to a 10 – second flame
impingement from a butane lighter or burner, flame
is reapplied 5 seconds after the flame on the cup
extinguishes after the first exposure.
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- Developing a Requirement in the Standard • The time the cup continues to burn after the ignition
source is removed is timed.
• No more than 30 seconds “after burn” is allowed
after any one ignition.
• No more than 300 total seconds of “after burn” is
allowed for the entire test (20 total exposures).
- The Year is Now 2009 • In 2009 the ASTM F2417 Fire Safety for Candles gets
re-approved and includes a test method and a
flammability requirement for plastic tealight cups.
• Some on task group were of the opinion that
components within the candle could effect the
properties of the polymer. They recommended a
study to examine the effect of exposure of fragrance
components, to various polymers, to see if cracking
or changes in flammability could occur.
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- Summer 2009 • One task group member conducts a study with
fragranced tealight candles in plastic cups.
• Company used their wax base and fragrances.
• Selected fragrances based on suspicions of which
ones would be most aggressive to cup material being
used.
• Company fragranced candles at their typical
fragrance load concentrations.
- Summer 2009 • Candles were aged for various lengths of time
up to 45 days at 117F (47C).
• Candles were use tested using ASTM F2417
method. After completion of candle fire safety
testing the empty cups were evaluated for
flammability and cracking.
• Observed no change in burn characteristics of
the candle and no change in flammability of
the cup compared to virgin cups– also no
cracking of the cup was observed.
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- Fall 2009 • Data from testing is presented to task group – this
data basically showed no detectable difference in the
flammability of the cups due to exposure of the base
wax and fragrance. Additionally the integrity of the
cup had not changed, i.e. no cracking or fogging of
the cup was observed.
• Still not all members of the task group are convinced.
Some feel that fragrance exposures may play a role
in the flammability and chemical stability of the
tealight cups.
• A smaller task group is formed to design an
experiment to evaluate the issue further.
- Winter 2009 •
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The smaller task group decided not to use same fragrances as that
used in the 1997 Okometric study for several reasons. First, it was the
understanding of the group that the fragrances used in Okometric
study were proprietary. Secondly they felt the fragrances used may
not represent what is commonly used in the US
Smaller task group determined a list of fragrance components to
include in test based on tonnage of fragrance components sold as
reported by FMA for air care. These compounds were later segregated
based on chemical functional groups
24 individual fragrance components and 3 diluents were chosen for
the testing.
Total fragrance-component loading in the candles was at 20% by
weight. The smaller group felt that this was a worse case scenario
and wanted to evaluate what might happen at this level and perhaps
reduce the level in future testing.
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List of Compounds Evaluated
- Test Design • 4 different types of cups are used to evaluate fragrance
exposures – i.e. these represent different polymers / different
manufacturers.
• Polymer materials chosen for test are either currently used as
cup materials or are clear plastic materials that might be used in
the future.
• Candles are made in a paraffin wax base with 20% “fragrance
loading” and poured into cups.
• Candles were placed in heated chambers at 45°C for 1 week of
time to simulate accelerated aging.
• Candles and “virgin cups” provided to the laboratories in a blind
fashion.
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- Test Design • Cups were placed in freezer to help facilitate removal
of wax – wax was wiped out with a cloth.
• Cups were evaluated for cracking and hazing.
• Cups that had previously been filled along with virgin
cups were tested for flammability using ASTM F2417
Fire Safety for Candles.
• Results from cups exposed to extremely HIGH
fragrance load were later compared to “virgin cups”
results.
- Results as of 2010 • At the 20% fragrance component level all
cups showed evidence of hazing.
• Cracking was observed in two of the
polymers when exposed to different
fragrance components at a 20% loading.
• Flammability of one polymer was adversely
affected by exposure to one fragrance
chemical groups at an extremely high use
level.
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Cracking and Cloudiness
Flammability Evaluation
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- What Important Information
Have We Learned? Under certain exposure conditions and fragrance
component levels it is possible:
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To interact with polymers used in tealight cups to
make them cloudy or hazy
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To react with polymers in such a way as to cause
cracking
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To interact with polymers in such a way as to
affect the flammability characteristics of the material.
- “Back to the Future” • You are all invited to attend the ASTM
Sub-Committee meeting Friday morning to add
your input.
• What are we going to be discussing?
• Addition of an Appendix to the standard
– non mandatory.
• Appendix to include guidance on aging of cups
with product and testing of tealight cups after
exposure.
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Thank You to the ASTM Task
Group and Participating Companies
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Arylessence
Auralites
Beauty Avenues
Belmay
Blyth
BV
CRC Polymers
• Hanna’s Candles
• Health Canada
• Lumi-Lite Candle
Company
• Root Candle
• SABIC
• SEA Ltd
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