Can you use any glass jar for a candle?
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No. A candle heats its jar from the inside for hours, unevenly, and hottest near the end of its life, and ordinary glassware is not made or checked for that. The glass industry's answer is ASTM F2179, a voluntary specification for annealed glass containers produced for use as candle containers, which sets annealing, scratch and thermal shock requirements. Choose jars whose maker or seller tells you, in writing, that they are made for filled candles and to which edition of F2179, and then burn test every build to the end. This page explains what F2179 covers, what to ask a supplier, why reused and decorative jars are a gamble, and what CPSC jar recalls show.
What ASTM F2179 is, and what it covers
ASTM F2179 is one of six ASTM candle standards that the U.S. Consumer Product Safety Commission lists in its business guidance for candle makers [1]. Like the others, it is voluntary in law. Retailers write ASTM standards into their vendor requirements, which is how a voluntary standard becomes a condition of a sale.
The current edition is F2179-26, listed as active on the ASTM store (page last updated May 28, 2026) [2]. Its title is Standard Specification for Annealed Glass Containers That Are Produced for Use as Candle Containers, and its scope says it is specifically for glass containers intended to be used as filled candle containers [2]. Earlier editions, and the title CPSC still lists, read "Annealed Soda-Lime-Silicate Glass Containers" [1] [3]. The 2026 title no longer names the glass type; what that change means in practice is in the purchased text, which is not reproduced or paraphrased here.
What the published summaries say the standard does:
- It sets annealing, thermal shock and scratch test requirements. ASTM's abstract for the 2020 edition says containers "shall conform to specified annealing and thermal shock requirements" and undergo scratch testing so that residual stress is reduced to a commercially acceptable level [3]. ASTM Standardization News describes F2179 as establishing scratch test and temper specifications for proper annealing, plus thermal shock requirements, and says glass that passes it makes fires due to an imperfection in the glass itself less likely [4].
- It covers filled candle containers only. The 2020 revision narrowed the scope to filled candle containers and stated what it excludes: votive holders, hurricanes and glass holders used with freestanding candles [5]. The 2026 scope keeps that exclusion [2]. A glass votive holder or hurricane is an accessory, which falls under a different standard, ASTM F2601 (see votives and tealights).
- It added rules for decorated and processed glass. TÜV SÜD's summary of the 2020 revision reports new definitions (candle container, glass manufacturer and others), changes to the annealing sections for containers that are further processed, and a new section on secondary glass operations [5]. Secondary operations are the things done to glass after it leaves the furnace: printing, frosting, coating, cutting. That matters because a jar that met the standard as it was made can be changed by what is done to it afterward.
All six ASTM candle standards, their current editions and how they relate are on the ASTM candle standards. The fire safety standard for the finished candle, F2417, was itself revised in 2026 and, according to SGS's summary, now includes a definition of a candle container and new requirements for candle containers [6]; the summary does not describe them.
Annealing and thermal shock, in plain terms
Glass is formed hot and cools from the outside in. If it cools unevenly, stress is locked into it. Annealing is the controlled reheating and slow cooling that relieves that stress. A poorly annealed jar can look perfect and still carry stress that a hot flame finds.
Thermal shock is what happens when one part of the glass is much hotter than another. A burning candle does exactly this: the glass beside the melt pool is hot while the base and the glass above the wax line are cooler. Late in the candle's life the flame sits low, close to the bottom and the walls, and the difference grows. A stressed, scratched or thin spot is where a crack starts.
That is why "it held boiling water" or "it is oven safe" does not settle the question. Those are different heat patterns from a flame burning down inside the jar, session after session, over the candle's whole life.
What to ask before you buy a jar
A supplier selling glass for candles should be able to answer these. Ask in writing and keep the answer with your batch records.
| Question | Why it matters |
|---|---|
| Is this jar made and sold for filled candles? | F2179 applies only to containers produced for that use [2]. |
| Does it meet ASTM F2179, and which edition? | "Meets ASTM" without an edition cannot be checked. The active edition is F2179-26 [2]. |
| Who made the glass, and does the maker test to F2179 or only the reseller? | The 2020 revision defines the glass manufacturer's role [5]. |
| Has anything been done to it after forming (printing, frosting, spray coating, cutting, a decal)? | Secondary operations are addressed separately in the standard [5], and a coating may also burn. |
| Is a test report or certificate available for this item and lot? | A report ties the claim to the jar you are actually buying. |
| Does the maker state any limits on wick count, flame or burn conditions? | If the maker publishes limits for that jar, they are the most specific figures you will get. |
A yes to all of these still does not make a candle safe. It tells you the glass was made for the job. Whether your wick, wax and fill heat it beyond what it can take is something only your burn test shows.
Reused, upcycled and decorative jars
Makers often ask about jam jars, drinking glasses, wine bottles cut into tumblers, vintage pieces and thrifted glass. Some of them will burn without trouble. The difficulty is that you have no way to tell which.
| Jar | What you know | What you do not know |
|---|---|---|
| New jar sold for candles, with an F2179 statement and edition | What the maker claims and to which edition | How your build heats it (burn test) |
| New jar sold for candles, no statement | That someone markets it for candles | Whether it was annealed or tested to F2179 |
| Food jar (jam, sauce, baby food) | It survived a food process | Whether that process resembles a flame inside it; scratches from washing and reuse |
| Drinking glass, vase or decorative glass | Nothing about candle use | Annealing quality, wall thickness, coatings |
| Cut bottle or other glass you have altered | That the edge and wall were stressed by cutting | Everything after the cut |
| Vintage or secondhand glass | Its age | Its history of chips, scratches and heat |
For candles you burn at home, using a jar outside the first row is your own risk to judge. For candles you give or sell, the honest position is that you cannot vouch for the glass. If you do it anyway, burn test that exact jar style to the end, more than once, and keep the records. See what to give with a candle you give away for the gift case.
What the recalls show
CPSC recall notices are the clearest public evidence that jar failure is a real and recurring problem, including in candles sold by large companies.
| Recall | Date | Candle | What CPSC reported |
|---|---|---|---|
| Target, Threshold glass jar candles (23-255) | August 10, 2023 | 5.5 oz one-wick and 20 oz three-wick glass jar candles, some lidded | About 2.2 million units; jars can crack or break during use; 19 reports, one minor injury [7] |
| DEMDACO, Maril scented candles (25-250) | May 8, 2025 | 8 oz glass jar | About 3,000 units; glass container can crack or break while burning; three reports, no injuries [8] |
| Little Cow Company (26-241) | February 5, 2026 | 9 oz glass jar with screw top lid | About 1,140 units; jar can crack or break during use; two reports, no injuries [9] |
None of these notices gives a cause or a temperature. They do show the scale (from about a thousand units to millions) and that a small maker's 9 oz soy candle is subject to the same process as a national retailer's. What to do when a jar has cracked, and when to stop selling a jar, is on cracked or broken candle jars.
The jar still has to pass your burn test
Glass made to F2179 removes one cause of failure. Your build adds others: a wick too large for the diameter, a wick off center so the flame heats one wall, a multi-wick candle whose flames heat each other, or a candle burned too far down.
The clearest published numeric limits for jar temperature come from one retailer's buyer protocol. Kohl's Test Protocol 100-Z (February 2025), whose candle limits are unchanged from the earlier 100-Y, requires that the container of a filled candle, tealights included, not crack or break when tested, and that the outside surface of a glass or ceramic container stay at or below 175°F (79°C) during burning [10]. They are one buyer's requirements, built on F2417-17, with no legal force and separate from the ASTM text, and they are a sound target. How to take the reading is on how hot the jar gets, and how to measure it.
Comparing glass with tins, ceramic and concrete
F2179 is a glass standard only. If you are deciding between glass and another material, glass, tin, ceramic or concrete compares how each behaves under heat, how each fails and what each asks of your testing.
References
- U.S. Consumer Product Safety Commission, Candles Business Guidance, undated, read October 22, 2026. https://www.cpsc.gov/Business--Manufacturing/Business-Education/Business-Guidance/Candles
- ASTM International, ASTM F2179-26 Standard Specification for Annealed Glass Containers That Are Produced for Use as Candle Containers (store page, scope), last updated May 28, 2026. https://store.astm.org/f2179-26.html
- ASTM International, ASTM F2179-20 Standard Specification for Annealed Soda-Lime-Silicate Glass Containers That Are Produced for Use as Candle Containers (store page, scope and abstract; historical), read October 22, 2026. https://store.astm.org/f2179-20.html
- Doug Clauson, Increasing Candle Safety, ASTM Standardization News, March/April 2013 (posted July 26, 2016). https://www.astm.org/news/increasing-candle-safety-ma13
- TÜV SÜD, USA: ASTM Updates F2179, Consumer Products and Retail E-ssentials 6/2020, March 2020. https://www.tuvsud.com/pl-pl/newsletter/consumer-products-and-retail-essentials/e-ssentials-6-2020/usa-astm-updates-f2179
- SGS, ASTM Updates Candle Fire Safety Standard (SafeGuardS 096/26), July 14, 2026. https://www.sgs.com/en/news/2026/07/safeguards-09626-astm-updates-candle-fire-safety-standard
- U.S. Consumer Product Safety Commission, Target Recalls 2.2 Million Threshold Candles Due to Laceration and Burn Hazards, recall 23-255, August 10, 2023. https://www.cpsc.gov/Recalls/2023/Target-Recalls-2-2-Million-Threshold-Candles-Due-to-Laceration-and-Burn-Hazards-Sold-Exclusively-at-Target
- U.S. Consumer Product Safety Commission, DEMDACO Recalls Maril Brand Scented Candles Due to Laceration and Fire Hazards, recall 25-250, May 8, 2025. https://www.cpsc.gov/Recalls/2025/DEMDACO-Recalls-Maril-Brand-Scented-Candles-Due-to-Laceration-and-Fire-Hazards
- U.S. Consumer Product Safety Commission, Little Cow Company Recalls 9 oz Candles in Glass Jars Due to Fire, Burn and Laceration Hazards, recall 26-241, February 5, 2026. https://www.cpsc.gov/Recalls/2026/Little-Cow-Company-Recalls-9-oz-Candles-in-Glass-Jars-Due-to-Fire-Burn-and-Laceration-Hazards
- Kohl's, Private Brands Performance Claims Test Protocols 100, Protocol 100-Z: Candle (including freestanding, taper, tealight, votive, filled and novelty candles), revised February 2025 (current revision; candle limits unchanged from 100-Y, February 2023), read October 22, 2026. https://link.kohls.com/content/dam/klink/100-Z-CANDLE.pdf
