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? 1
- 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. 2
- 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 3
- Early Actions of ASTM F15.45 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. 4
- 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. 5
- 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 6
- FTIR Analysis of Cups - 7
- Recalls Continue - January 2007 Sally Foster tealight cup can melt or ignite. February 2008 Christmas Tree Shops tealight cup can melt or ignite. 8
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 9
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. 10
- 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. 11
- 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 12
Example of Test in use Position 13
- 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. 14
- 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. 15
- 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. 16
- 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. 17
- 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. 18
- 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 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. 19
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. 20
- 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. 21
Cracking and Cloudiness Flammability Evaluation 22
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- What Important Information Have We Learned? Under certain exposure conditions and fragrance component levels it is possible: To interact with polymers used in tealight cups to make them cloudy or hazy To react with polymers in such a way as to cause cracking 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. 24
Thank You to the ASTM Task Group and Participating Companies Arylessence Auralites Beauty Avenues Belmay Blyth BV CRC Polymers Hanna s Candles Health Canada Lumi-Lite Candle Company Root Candle SABIC SEA Ltd 25