Why Is My Candle Giving Off Black Smoke? We Explain All

Sometimes, what gets us through a long, hard day in the office is the thought of getting home and spending the evening relaxing. A nice meal, a warm bubble bath, and, of course, the delightful flicker of our favorite candle. Nothing speaks more of ridding the stresses of the day and recharging those slightly depleted batteries.

However, things don’t always go to plan, and finding that your candle isn’t burning how it should is sure to put a dampener on any relaxation ideas you may have. In our candle section here at Flame Stuff we look into various different reasons that your candles may not be burning appropriately and in this article, we are going to concentrate on the output of smoke.

We will check out how much is normal, what color it should be, and how to fix any problems. So, keep reading and add to your ever-growing knowledge base of candle burning.

There are various causes for black smoke being emitted from a candle. The most common is if the wick is too long, the candle has been burning for too long and is therefore too hot, or if the candle is near a draft. Each of these scenarios is both easily fixed and preventable.

Are Candles meant to Smoke?

A well-made candle that is burning appropriately should never give off permanent smoke. You may find that it does generate a little from time to time and when it does it should be white to grey in color.

Smoke is in fact carbon particles that have not been burned as the candle breaks down. Much of the carbon created when you have a flaming candle is converted into carbon dioxide but sometimes a little does escape which is why you may see the odd smoke trail.

Drafts and strong air currents can also cause your candles to smoke. You must always ensure that your candles are only used in well-ventilated areas and kept away from drafts.

However, should your candle start to produce black smoke it is time for a quick fix to alleviate the problem. Whilst the levels of potential toxins produced by black smoke from your candle are not considered to be enough to cause any health concerns it still needs to be rectified.

Why is my Candle blowing Black Smoke?

The main cause of any black smoke is a build-up of carbon on the wick. This generally happens when the wick is too long. As your candle burns and the wax melts it is pulled up through the wick to fuel the flame. When the wick is too long it is unable to pull all the wax to the flame resulting in black smoke.

Whilst most of the time the problem will be a long wick there are other causes of black smoke being emitted from your candle, and you’ll be pleased to hear that most are fixable or preventable.

Other causes of black smoke are:

  • Believe it or not, your candle can get too hot if burned for too long. Should the wax begins to melt and produce a pool rather than be drawn up through the wick this can cause an irregular flame and of course, black smoke.
  • Dust and detritus! If you don’t burn your candle regularly it’s easy for dirt and dust to collect on top which will cause soot to be generated once you do light your candle again.
  • Chemical composition. If the fragrance or coloring used to make your candle is cheap or the ratios are not managed correctly they can cause your candle to blow out black smoke when lit. This can also apply to the wax quantities and using the wrong wick type.
  • Drafts. Fans, heaters, and air conditioning vents all produce enough air to affect the flame on your candle. An irregular flame in turn can cause the black smoke we are hoping to avoid.

How do you prevent Black Smoke from Candles?

There are various remedies to prevent black smoke and some will rectify it should your candle be blowing it off. These, however, will be dependent on the cause.

Keeping your wick trimmed and in the best condition is the best way to prevent black smoke. ¼” is the optimum length. Trim after every use to keep both it and your candle in tip-top shape. Burn times are also crucial as you don’t want your candle to get too hot. Always follow the manufacturer’s guidelines for each individual candle.

Always replacing lids on jarred candles, when they are not in use, will keep dust, dirt, and detritus from gathering on the top. If your candles aren’t in a container with a lid and you don’t burn them regularly make sure you store them in a dust-free environment between burns. This can be simply bagging them up and popping them in the cupboard.

If your black smoke problem is down to the assembly, there is little you can do other than avoid manufacturers where you have encountered issues going forward. Generally, cheaper candles or those bought from hobbyists will pose the most risk.

Is Black Smoke from a Candle dangerous?

A properly burning candle should not produce any smoke and while the health risks and both small and rare it is worth bearing in mind that black smoke can cause adverse reactions in some cases.

If you already suffer from repository conditions such as asthma or COPD then you are at greater risk from any black smoke that your candle may produce, although this is still small. It is always worth taking into consideration any pets you may have, although the risks of smoke inhalation are similar to those of humans.

Whilst direct drafts should be avoided never burn a candle in an unventilated room. Over an extended period, this can cause a build-up of carbon monoxide which causes significant health complications.

Most importantly, never go to sleep and leave any candles burning. Notwithstanding the fire risk burning the candle for too long will result in it becoming too hot and blowing off black smoke. You don’t want to be breathing that in whilst you are sleeping.  


Candles should burn relatively smoke-free; if they are burning black smoke there is most certainly an issue. Once you have determined the problem then in most cases trimming the wick will resolve it. In the case of a manufacturing issue then there is nothing you can do but avoid the particular seller in the future.

Candles need care and if you take care of them properly you should have no troubles enjoying the relaxing experience that they can bring. Keep their wicks short, not burn for too long and the lids on when not in use and you should always be good to go.

If your candle is producing excessive smoke or continues to produce black smoke after you have taken preventative measures, then it should be distinguished and discarded once completely cooled.