Candle Burning - GAI Engineers · 7.2 Six (6) Candles, Container – Small Candleholder, Clean...

Candle BurningStudy

Issued:September 15, 2011

© 2011 GAI Engineers

Table of Contents

GAI Engineers ……………..….……….……………………… 1

Introduction ……………………….………………………...... 2

Study Protocol ……….……….………………………….…… 3

Study Photographs ……………………………….......…….. 4

Study Data ………………………………………….…....…….. 5

Conclusions ……………...…………………………………….. 6

References ……………...…………………………………….. 7

Section 1

GAI ENGINEERS

GAI Engineers is a forensic engineering firm specializing in origin and cause investigation, failureanalysis, accident reconstruction, and other technical support for insurance companies, law firms,fire investigators, manufacturers and private parties throughout New England. Since our founding in1934, GAI has investigated and resolved thousands of cases involving property loss, premiseliability, personal injury, and product liability.

At GAI, our mission is clear: Through rigorous investigation, objective analysis, reliable reporting,accurate assessment, and unassailable expert testimony —we assist each client to understand andsolve complex technical problems, resolve claims and litigation, and mitigate or eliminate loss.Working on behalf of insureds, claimants, plaintiffs, and defendants, GAI understands that clientneeds usually stem from the demands of an insurance contract or legal dispute. Our engineers havehelped countless clients achieve cost-effective resolution of claims, maximum recovery fromsubrogation, strong defense on insured liability, and favorable settlements on behalf of privateparties.

Experienced in litigation, GAI professionals provide legal support and expert testimony forprosecutors, plaintiffs and defendants, product manufacturers, utilities, and insurers. Our engineersassist as non-testifying experts in preparing and reviewing depositions, and evaluating technicaldocuments obtained through discovery. We also help determine the underlying cause of a loss, andwhether a reasonable basis for subrogation exists. As testifying witnesses, GAI effectively rendersopinions on topics ranging from electrical and mechanical engineering issues, to electrical fires, gasexplosions, and product design, manufacture, service, and installation. With valid scientific methodour hallmark, we successfully withstand Daubert motions and consistently qualify as expertwitnesses in state and federal courts on civil and criminal matters.

Since our inception, GAI has been continuously operated and locally owned by only two families —a system that has ensured reliability, quality, and continuity of service for our clients. Today, underthe direction of Andrew J. Williams, P.E., GAI continues a longstanding tradition of responsiveservice, accurate analysis, thorough reporting, and defensible presentation of findings and opinionsfor insurers, attorneys, and private parties throughout New England and beyond.

Section 2

INTRODUCTION

Candles have been used throughout the world for thousands of years. The Romans are creditedwith some of the first use of candles, fueled by tarrow, the rendering of animal fat. During theMiddle Ages, beeswax was used as a fuel and later, during the whaling days of the 18th century,sperm whale fat was a commonly used fuel. It was during the 19th century that candle-makingbecame mechanized and paraffin wax began fueling candles.

Roughly 90% of candle manufacturer’s in the United States are members of the National CandleAssociation (“NCA”). According to the NCA, more than 1 billion pounds of wax are used forcandle-making annually. About 7 out of 10 households use candles. Candles are burned most oftenin the living room (42%), in the kitchen (18%) and in the bedroom (13%).

Though a burning candle may look simple, the chemistry and physics are quite complex. In 1861,the famous English scientist, Michael Faraday, wrote “The Chemical History of the Candle” a seriesof six lectures explaining how burning candles represent almost all natural phenomenons known tomankind. Topics such as combustion and heat transfer both play a role. At the wick, molten wax isvaporized and pyrolized (the larger molecule breaks down into smaller molecules due to heat).These smaller molecules are combustible and mix with the surrounding air and heat to combust(burn). The products of combustion are lighter than the surrounding cool air, causing the flame torise. The heat from combustion causes the solid wax near the wick to melt. The molten wax isdrawn up the wick due to capillary action, continuing the process.

The anatomy of a candle has not changed significantly since early times. All candles are constructedwith a solid fuel and wick. The most common solid fuel is petroleum-derived paraffin wax,accounting for roughly 85% of all candles sold.

The term “paraffin” refers to the alkane family of hydrocarbons, with the general formula ofCnH2n+2. Paraffin wax usually refers to alkanes where 20≤n≤40, with the average being n=25.Colorants and fragrances are the most common additives to candle wax.

Wicks are most often made from braided fibers of cotton. The thickness of the wick is directlyproportional to the burn rate. Wicks can have cores of paper or metal; these improve the structuralstability of the wick. Typical metals used are zinc and tin; lead was used for many years, but hasbeen banned for some time now. Wicks are usually tethered to the bottom of the candle using ametal wick tab, with base diameters ranging from 15mm to 20 mm, and neck heights ranging from 3mm to 9 mm.

A study of candle-related fires from 2004-2007 by the National Fire Protection Association revealedthere were 42 candle-related fires per day during that timeframe. About 20% of these candles wereleft unattended. Roughly 1/3 of all of the candle-related fires occurred in a bedroom. Historically,the occurrence of candle-related fires increased annually in the 1990’s, with 2001 having the mostcandle-related fires at almost 19,000 that year. Since 2001, the number of annual candle fires hasdecreased steadily.

Though the increase in candle-related fires in the 1990’s created concern, it should be noted that thenumber of candles sold annually in that decade increased dramatically. In 1997, the ConsumerProduct Safety Commission tasked the American Society of Materials and Technology to create a

Section 2

standard of safety for candles. Though six standards related to candle fire safety have been issued,the most referenced standard is ASTM F2417 – 09, Standard Specification for Fire Safety for Candles.This standard provides requirements for parameters such as flame height, secondary ignition,container failure, stability, and others.

A cursory internet search of the burning characteristics of candles reveals tremendous variability ofburn times. Many websites suggest measuring the initial weight of a candle, burning it for 3-4 hours,and then measuring the final weight; this yields an average burning rate to determine the ultimatecandle burn time. Other websites give burn times for various size candles. For a 22 ounce glass jarcandle, burn times were found ranging from 110 to 180 hours. For a 3x3 pillar candle, burn timeswere found between 40 to 50 hours. For an 8” taper candle, burn times were found between 7 and9 hours.

All fire investigators have encountered candles in their casework. One of the most commonquestions asked of homeowners after a fire is about their use of candles. For various reasons, manyhomeowners and occupants are reluctant to admit burning candles at the time of the fire. There aresometimes questions as to whether a candle would have self-extinguished prior to the onset of fire,or how much candle should be remaining based on a known burn time.

GAI set out to understand general burn times of a variety of candle types under normal conditions.A test protocol was developed to encompass a wide variety of candle use scenarios. The burn timeof each candle and a sampling of burn rates were recorded.

Forensic Engineering and Fire Investigation since 1934

Section 3

378 Page Street – Building 10Stoughton, MA 02072-1141

[email protected]: 781-297-3500

Fax: 781-297-7050

PROTOCOL

1.0 PROTOCOL TITLE: Candle Burning Study

2.0 PROTOCOL LOCATION(S): GAI Engineers378 Page Street – Building 10Stoughton, MA

3.0 PROTOCOL DATE & TIME: Not Applicable

4.0 ORIGINATOR(S): Andrew J Williams, P.E.

5.0 ORIGINATION DATE: July 14, 2010

6.0 PURPOSE/SCOPE:

The purpose of this protocol is to study the combustion characteristics of burning candles. Varioustype and brands of candles will be used. The fuel consumption versus time and end-of-lifeperformance will be evaluated.

7.0 TOOLS/ EQUIPMENT:

7.1 Six (6) Candles, Container - Small Glass Jar, French Vanilla Scented7.2 Six (6) Candles, Container – Small Candleholder, Clean Linen Scented7.3 Six (6) Candles, 8” Taper, White with Glass Candleholders7.4 Six (6) Candles, 3” x 3” Pillar, White with Three (3) Metal Stands7.5 Six (6) Candles, Votive, White, with Three (3) Glass Holders7.6 Six (6) Candles, Tea Light Style with Metal Holders, White

8.0 PROCEDURE:

8.1 Photograph packaging and each candle. Number each candle with label maker.Measure candle height and wick height for each candle.

8.2 Set up groups of candles on cementitious covered table under Fume Hood. Placetwo layers of cotton paper towels under all groups of candles. Photograph eachcandle group as well as overall table.

Section 3

8.3 Light all candles using butane lighter. Measure height of each candle andphotograph each candle group at intervals of one hour for the first 8 hours. If anycandle self-extinguished prior to being consumed, note the candle number andtime and re-light. If candles are still burning at 8 hours, extinguish candle byblowing out flame.

8.4 For candles that were extinguished, repeat Step 8.3 until candle is consumed. Afterthree 8 hour intervals, measurements and photographs need only be taken at theend of the 8 hour interval.

8.5 Photograph each candle when consumed, including any damage to paper towels.

CANDLE BURNING STUDY PHOTOGRAPHS

Section 4

1. Study, showing Glass Jar Container Candles.

2. Glass Jar Container Candles, showing Close-Up.


Section 4

3. Glass Jar Container Candles, showing Label.

4. Study, showing Glass Candleholder Container Candles.


Section 4

5. Glass Candleholder Container Candles, showing Close-Up.

6. Glass Candleholder Container Candles, showing Label.


Section 4

7. Study, showing Taper Candles.

8. Taper Candle, showing in Holder.


Section 4

9. Study, showing Pillar Candles.

10. Pillar Candles, showing on Holder.


Section 4

11. Study, showing Votive Candles.

12. Votive Candles, showing in Holder.


Section 4

13. Study, showing Tea-Light Candles.

14. Tea-Light Candles, showing Close-Up.


Section 4

15. Study, showing Set-Up prior to Lighting.

16. Study, showing Set-Up after Lighting.


Section 4

17. Set-Up, showing Glass Jar Container Candles after Lighting.

18. Set-Up, showing Glass Candleholder Container Candles after Lighting.


Section 4

19. Set-Up, showing Taper Candles after Lighting.

20. Set-Up, showing Pillar Candles after Lighting.


Section 4

21. Set-Up, showing Votive Candles after Lighting.

22. Set-Up, showing Tea-Light Candles after Lighting.


Section 4

23. Set-Up, showing Tea-Light Candles during Burning.

24. Set-Up, showing Taper Candles during Burning.


Section 4

25. Set-Up, showing Votive Candles during Burning.

26. Set-Up, showing Pillar Candles during Burning.


Section 4

27. Set-Up, showing Glass Candleholder Container Candles during Burning.

28. Set-Up, showing Glass Jar Container Candles during Burning.

Candle Burning Study - Burn Time

Sample Country Manufacturer's ActualNumber Type Size Color Fragrance Manufacturer Distributor of Origin Burn Time (Hours) Burn Time (Hours)

1 Container - Glass Jar 3.7 Ounce Off-White French Vanilla Yankee Candle Company Yankee Candle Company United States 25-40 29.02 Container - Glass Jar 3.7 Ounce Off-White French Vanilla Yankee Candle Company Yankee Candle Company United States 25-40 24.33 Container - Glass Jar 3.7 Ounce Off-White French Vanilla Yankee Candle Company Yankee Candle Company United States 25-40 28.04 Container - Glass Jar 3.7 Ounce Off-White French Vanilla Yankee Candle Company Yankee Candle Company United States 25-40 27.05 Container - Glass Jar 3.7 Ounce Off-White French Vanilla Yankee Candle Company Yankee Candle Company United States 25-40 27.56 Container - Glass Jar 3.7 Ounce Off-White French Vanilla Yankee Candle Company Yankee Candle Company United States 25-40 26.0

AVERAGE: 27.0STANDARD DEVIATION: 1.7


1 Container - Glass Candleholder 4 Ounce White Clean Linen S.C. Johnson & Son Stop & Shop Canada 22 32.02 Container - Glass Candleholder 4 Ounce White Clean Linen S.C. Johnson & Son Stop & Shop Canada 22 32.03 Container - Glass Candleholder 4 Ounce White Clean Linen S.C. Johnson & Son Stop & Shop Canada 22 32.04 Container - Glass Candleholder 4 Ounce White Clean Linen S.C. Johnson & Son Stop & Shop Canada 22 28.55 Container - Glass Candleholder 4 Ounce White Clean Linen S.C. Johnson & Son Stop & Shop Canada 22 28.56 Container - Glass Candleholder 4 Ounce White Clean Linen S.C. Johnson & Son Stop & Shop Canada 22 29.5



1 Taper - In Crystal Holder 8" White None Target Brands Target Vietnam Unknown 4.52 Taper - In Crystal Holder 8" White None Target Brands Target Vietnam Unknown 53 Taper - In Crystal Holder 8" White None Target Brands Target Vietnam Unknown 54 Taper - In Crystal Holder 8" White None Target Brands Target Vietnam Unknown 5.255 Taper - In Crystal Holder 8" White None Target Brands Target Vietnam Unknown 76 Taper - In Crystal Holder 8" White None Target Brands Target Vietnam Unknown 7



1 Pillar 3" x 3" White None Target Brands Target Vietnam Unknown 352 Pillar 3" x 3" White None Target Brands Target Vietnam Unknown 24.53 Pillar 3" x 3" White None Target Brands Target Vietnam Unknown 14.75


4 Pillar - On Metal Plate 3" x 3" White None Target Brands Target Vietnam Unknown 29.55 Pillar - On Metal Plate 3" x 3" White None Target Brands Target Vietnam Unknown 316 Pillar - On Metal Plate 3" x 3" White None Target Brands Target Vietnam Unknown 31


Section 5

Candle Burning Study - Burn Time


1 Votive 1.34 Ounce White None Greenbriar International Dollar Store India Unknown 2.52 Votive 1.34 Ounce White None Greenbriar International Dollar Store India Unknown 2.753 Votive 1.34 Ounce White None Greenbriar International Dollar Store India Unknown 2.75


4 Votive - In Glass Holder 1.34 Ounce White None Greenbriar International Dollar Store India Unknown 12.755 Votive - In Glass Holder 1.34 Ounce White None Greenbriar International Dollar Store India Unknown 166 Votive - In Glass Holder 1.34 Ounce White None Greenbriar International Dollar Store India Unknown 16



1 Tea-Light 1.34 Ounce White None Nantucket Distributing Christmas Tree Shops Thailand Unknown 1.52 Tea-Light 1.34 Ounce White None Nantucket Distributing Christmas Tree Shops Thailand Unknown 1.53 Tea-Light 1.34 Ounce White None Nantucket Distributing Christmas Tree Shops Thailand Unknown 1.5


4 Tea-Light - In Metal Holder 1.34 Ounce White None Nantucket Distributing Christmas Tree Shops Thailand Unknown 3.55 Tea-Light - In Metal Holder 1.34 Ounce White None Nantucket Distributing Christmas Tree Shops Thailand Unknown 3.56 Tea-Light - In Metal Holder 1.34 Ounce White None Nantucket Distributing Christmas Tree Shops Thailand Unknown 3.5


Section 5

Candle Burning Study - Burn Rate

Sample Start HeightNumber Type (Inches) 2 4 6 8 10 12 14 16 18 20 22 24

1 Container - Glass Jar 2.5 2.13 2.00 1.25 1.25 1.50 1.50 1.25 1.00 1.00 0.88 0.38 0.632 Container - Glass Jar 2.5 2.13 2.00 1.25 1.25 1.25 1.50 1.25 1.00 1.00 0.50 0.50 0.503 Container - Glass Jar 2.5 2.13 2.00 1.25 1.25 1.50 1.50 1.25 1.00 1.00 0.75 0.13 0.134 Container - Glass Jar 2.5 2.13 2.00 1.25 1.25 1.50 1.50 1.25 1.00 1.00 0.50 0.50 0.505 Container - Glass Jar 2.5 2.13 2.00 1.25 1.25 1.50 1.50 1.25 0.88 1.00 0.50 0.50 0.506 Container - Glass Jar 2.5 2.13 2.00 1.25 1.25 1.50 1.50 1.25 1.00 1.00 0.75 0.38 0.38

Minimum Burn Rate: -0.25 Inches/HourMaximum Burn Rate: 0.75 Inches/Hour


1 Container - Glass Candleholder 3 2.38 2.00 1.75 1.75 2.00 1.75 1.25 1.25 0.75 1.38 1.25 1.252 Container - Glass Candleholder 3 2.38 2.00 1.50 1.50 1.75 1.63 1.25 1.25 0.75 1.38 1.25 1.253 Container - Glass Candleholder 3 2.25 2.00 1.25 1.25 1.75 1.63 1.25 1.13 0.75 1.38 1.25 1.254 Container - Glass Candleholder 3 2.25 2.00 1.25 1.25 1.75 1.63 1.25 1.00 0.75 1.38 1.13 1.135 Container - Glass Candleholder 3 2.25 2.00 1.25 1.25 1.75 1.63 1.13 1.00 0.75 1.38 1.25 1.256 Container - Glass Candleholder 3 2.25 2.00 1.13 1.13 1.75 1.63 1.25 1.25 0.75 1.38 1.25 1.25



1 Taper - In Crystal Holder 8 5.50 1.00 E E E E E E E E E E2 Taper - In Crystal Holder 8 5.50 2.00 E E E E E E E E E E3 Taper - In Crystal Holder 8 5.50 2.00 E E E E E E E E E E4 Taper - In Crystal Holder 8 5.50 2.25 E E E E E E E E E E5 Taper - In Crystal Holder 8 5.50 3.00 0.75 E E E E E E E E E6 Taper - In Crystal Holder 8 4.50 3.00 0.50 E E E E E E E E E

Minimum Burn Rate: 1.50 Inches/HourMaximum Burn Rate: 4.50 Inches/Hour

KEY: C = Could not be Measured E = Extinguished

Height at Hour (Inches)



Section 5

Candle Burning Study - Burn Rate


1 Pillar 3 2.50 2.50 1.50 1.50 1.50 1.75 1.25 1.13 C C C C2 Pillar 3 2.50 2.50 1.50 1.50 1.50 1.75 1.25 1.13 C C C C3 Pillar 3 2.50 2.50 1.50 1.50 1.50 1.25 1.25 C C C C C4 Pillar - On Metal Plate 3 2.50 2.50 1.50 1.50 1.50 1.25 1.25 1.13 C C C C5 Pillar - On Metal Plate 3 2.50 2.50 1.50 1.50 1.25 1.75 1.25 1.38 C C C C6 Pillar - On Metal Plate 3 2.50 2.50 1.50 1.50 1.50 1.75 1.25 1.38 C C C C



1 Votive 1.5 0.75 E E E E E E E E E E E2 Votive 1.5 1.00 E E E E E E E E E E E3 Votive 1.5 0.50 E E E E E E E E E E E4 Votice - In Glass Holder 1.5 1.00 1.00 0.50 0.50 0.50 0.38 E E E E E E5 Votice - In Glass Holder 1.5 1.00 1.00 1.00 1.00 0.75 0.38 0.13 C E E E E6 Votice - In Glass Holder 1.5 1.00 1.00 1.00 1.00 0.75 0.38 0.13 C E E E E



1 Tea-Light 0.5 E E E E E E E E E E E E2 Tea-Light 0.5 E E E E E E E E E E E E3 Tea-Light 0.5 E E E E E E E E E E E E4 Tea-Light - In Metal Holder 0.5 0.25 E E E E E E E E E E E5 Tea-Light - In Metal Holder 0.5 0.25 E E E E E E E E E E E6 Tea-Light - In Metal Holder 0.5 0.25 E E E E E E E E E E E


KEY: C = Could not be Measured E = Extinguished




Section 5

Section 6

CONCLUSIONS

The results of the candle burning study demonstrate some of the challenges of understanding howcandles burn.

Both candles that listed burn times burned at least as long as their rating, with the glass candleholdercontainer candle burning almost 50% longer than their rating

The height of the container candles and the votive candles in candleholders were difficult tomeasure. Wax accumulated along the upper edges of the container and then melted down later dueto flame impingement. As expected, over the 24 hour recording period for candle heights, allcandles showed a downward trend.

Candles without containment burned much differently than when contained. Without containment,the votive and tea-light candles softened and spread, reducing the amount of fuel available to thewick.

The taller candles without containment tended to melt down extremely unevenly. The pillar candletypically had one section of the sidewall melt open. The taper candles had significant wax melt thatwas never consumed.

Though all candles were burned until extinguishment, none ignited their cotton paper towels. Nocandles experienced container failure or secondary ignition.

In summary, this study has established some baseline burn times for a variety of candles. The burnrate of most candle types with respect to their height is extremely variable. It appears that burn rateis only reliable in taper candles.

Section 7

REFERENCES

1. Ahrens, Marty, Home Candle Fires, National Fire Protection Association – Fire Analysis andResearch Edition, June 2010.

2. ASTM F2417-09, Standard Specification for Fire Safety for Candles, published by ASTMInternational, Issued 2009.

3. Matthai, Michael, and Petereit, Norbert, The Quality Candle, SOFW Journal, Volume 130,Number 10, 2004.

4. Hamins, Anthony, Bundy,Matthew, and Dillon, Scott, Characterization of Candle Flames,Journal of Fire Protection Engineering, Volume 15, Number 4, November 2005.

5. National Candle Association website, About Candles, Researched September 2011.

6. Faraday, Michael, The Chemical History of a Candle, Given at Royal Institution of Great Britain,1860-1861.

378 Page Street – Building 10Stoughton, MA 02072781-297-3500 (main)781-297-7050 (fax)

[email protected]

Candle Burning - GAI Engineers · 7.2 Six (6) Candles, Container – Small Candleholder, Clean...

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