Which Jars and Containers Are Safe for Candles?
Short answer
Use a container sold for candles: thick, heat-tolerant glass, a food-grade tin, or a kiln-fired glazed ceramic. Avoid plastic and thin or unknown glass. CPSC lists ASTM F2179 as a voluntary standard for candle glass. Ask your supplier about it, then burn test the jar yourself.
Safety note. Test the exact jar you plan to sell, with your own wick and wax.
Use containers that were made to hold a burning candle. For glass, that means thick, heat-tolerant glass from a supplier who says it is for candles. CPSC lists ASTM F2179, a voluntary standard for annealed glass candle containers, so ask your supplier whether their jar meets it. I could not find a rule that says there is one safe material for everyone, so test the exact jar you plan to sell, with your own wick and wax.
What does the standard say about glass?
ASTM F2179-26 is titled "Standard Specification for Annealed Glass Containers That Are Produced for Use as Candle Containers." Its public page says the containers must meet annealing and thermal shock requirements and undergo scratch testing. It says the glass maker or secondary processor is responsible for compliance and for keeping test records. It excludes other glass items such as votive holders and hurricanes. CPSC's candle guidance lists F2179 among the voluntary standards, with F2058 for labeling and F2417 for fire safety. The full text is paid, so I cannot quote the test limits. What you can do is ask a supplier in writing if their jars meet F2179.
What does each material need?
Craftybase gives these rules of thumb for container materials:
- Glass. Candle-grade, thick-walled glass, ideally 3 mm or more at the base, with straight or slightly flared sides. It warns that drinking glasses and repurposed food jars use annealed glass that "can crack under rapid temperature changes", that vintage glass may be lead crystal, and that food jars vary in quality and are not recommended for products you sell. Narrow necks make trimming the wick and the melt pool harder.
- Tin. Food-grade tins with a smooth interior and a flat base. Decorative tins not made for food or cosmetic use can have coatings that react with fragrance oil, and tins with sharp inside corners can heat unevenly.
- Ceramic. Kiln-fired with a glazed interior and thick, even walls. Not air-dried clay, unglazed terracotta or pieces with an unknown firing temperature.
- Concrete. Dense mix, sealed inside with a food- or cosmetic-grade sealant.
- Plastic. Avoid it. Craftybase says it "softens, warps, and can release compounds when heated".
Note that Craftybase does not cite a formal standard for any of this, so treat it as one maker-supplier's guidance, not as a rule.
Are mason jars okay?
The pages I opened do not name mason jars. Craftybase's advice on repurposed food jars is that they are inconsistent and not recommended for candles you sell. I found no source stating that mason jars are made or tested to F2179, which covers containers produced for candles. If you try one for yourself, burn test it. For candles you sell, ask the jar's maker whether it is intended for candle use.
Worked example: a quick intake check
Say you are choosing between two 8 oz jars. This is a checklist and not a score, and the details are examples.
| Check | Jar A (candle supplier) | Jar B (craft store) |
|---|---|---|
| Sold for candles? | Yes, says so on the page | Not stated |
| F2179 asked and answered? | Supplier says yes, in writing | No answer |
| Base thickness | About 4 mm | Not measured |
| Burn test, 4 hours at 72 F | Jar peaks at 128 F (53 C) | Not run |
Jar A has paperwork and a test. Jar B has neither, so it is not ready to sell. A quick burn test also tells you about the wick, because CandleScience says an over-wicked container can get very hot and crack. See our jar heat guide for the 140 F rule of thumb and where it does and does not come from.
Common mistakes
- Using a drinking glass, a candy jar or a thrifted dish because it looks good.
- Assuming "microwave safe" or "oven safe" means candle safe.
- Skipping the burn test in a new container.
- Trusting one supplier's jar number for a different jar from another factory.
- Putting a candle in plastic or a thin decorative tin.
- Not telling customers what to do with the empty jar.
Questions
Do I need ASTM F2179 jars to sell candles?
CPSC calls ASTM F2179 voluntary. A shop, marketplace or insurer may ask for it, and I am not a lawyer, so ask them and check the current standard on the ASTM site.
Is ceramic as safe as glass?
It can be if it is kiln-fired and glazed inside, per Craftybase, but I found no standard that covers ceramic candle containers. Burn test it and watch for cracks and leaks.
Can I reuse jars from old candles?
I did not find a source I could open that covers this. If you do, clean them, check for chips and cracks, and burn test again. Do not reuse a jar that has cracked or chipped.
How BatchLab helps
The maker behind Ark & Dove built BatchLab for his own candle business. Materials and stock holds your jars with their pack sizes and cost per unit, and burn testing keeps a record of each test candle, which is where you can note the jar and its hottest reading. BatchLab does not check a jar's safety for you.
Sources
Reviewed , including a safety check against the sources above.