Do Wax Melts Kill Fish?

Are you a fish lover who also enjoys the aroma of scented wax melts? Maybe you are worried that the melts are releasing toxic fumes or chemicals into the air which could cause harm to your aquatic life?

Whether you keep tropical, marine, or cold-water fish here at Flame Stuff we aim to answer your concerns with regard to burning wax melts around your aquatic tanks. Keep reading to discover whether the effects of wax melts can indeed harm your fish.

Theoretically, wax melts shouldn’t endanger any aquatic life which you keep in your home. However, to be cautious, it is preferable to use unscented melts which are made from soy or beeswax. Ensure that you do not dispose of used melts down the sink to avoid contaminating the water system.

What Are Wax Melts?

Wax melts are similar to candles. The main reason people use them is to fragrance their rooms with a longer-lasting aroma. They are effectively candles but without the wick and are made using paraffin or soy wax, fragrance or essential oils, and candle wax dye.  

Wax melts come in many different scents, colors, shapes, and sizes. They are designed to be heated slowly on a burner which is usually made from ceramic, glass, or metal. The burners, also known as wax warmers, can be electric or manual. The manual burners use tea lights as the source of heat to burn the wax melt.

How Are Wax Melts Used?

To burn your wax melts, you will need a wax warmer. Your wax melt will be placed in a bowl on top of the burner which may or may not be removable and heated from underneath. As the wax melts, the fragrance is released.

Wax warmers can be electric or tealight. As one would assume the electric warmer plugs into the mains and eliminates the use of a flame to melt the wax. With the tealight burners, you place your candle under the dish and the wax is melted from the flame of the tealight.

The intensity of the scent can be controlled by managing the volume of wax melt that you use. This cannot be managed with a candle. The aroma from the wax melt is usually stronger with a tealight burner as it is being heated by a naked flame. However, they do tend to burn quicker and need replacing sooner.

NB: Never leave a burning tealight unattended.

Do Wax Melts Release Toxic Fumes?

There are two trains of thought when it comes to this question. On one side of the debate, you will find it being questioned as to whether burning candles and wax melts is bad for your health. However, on the other side of the coin, there is also the argument that wax melts (or candles) do not actually contain enough toxins to be dangerous.

Whilst there appears to be a lack of any peer-reviewed studies providing any conclusive evidence that burning candles or wax melts does release toxins that are detrimental to health it is worth remembering that any studies will relate to human health.

The debate around the release of toxins will largely be around candles and melts made from paraffin wax. Paraffin wax is derived from petroleum as a by-product in the manufacture of gasoline. Many candles are made from paraffin wax although less so with wax melts.

If in any doubt, and especially if you are questioning the use around your aquariums, it would be best to stick to melts produced using soy wax, beeswax, or other plant-based products.

What Chemicals are in an Aquarium? Will Wax Melts React with Them?

The type of aquarium that your run will determine what chemicals you will need to use to keep the water at the optimum to keep your fish safe and healthy. There are three main types of aquaria that you would keep at home.

Cold Water

Contrary to popular belief keeping cold water fish, such as a goldfish, isn’t as simple as filling up the bowl from the faucet and dropping your fish in. There still needs to be a certain level of maintenance to keep your fish healthy.

That said, you can use tap water to fill the tank as it will contain the correct minerals that a fish will require. However, tap water also contains chlorine which isn’t safe for your fish so you will need to use a de-chlorinator.

You will also need a filter starter. This will help regardless of whether you actually have a filter in your cold-water tank. This works by neutralizing the ammonia and nitrites that fish poop creates. The ammonia and nitrites are what is harmful to the fish!

Q: Will the chemicals in a cold-water fish tank react adversely with any fumes given off by a wax melt?

A: No


Unlike cold-water fish, tropical fish need a heater in their tank and the filter is not an optional extra. You can still use tap water to fill your tank and you will go through a process of treating and heating the water before you add any fish.

In terms of what you need to add to the water to optimize it for your new swimmers, it is no different from a cold-water tank although you may decide to add some live plants or a CO2 unit.

Different tropical fish may have slightly different pH and climate requirements which your local supplier can advise you on, but this should not have any effect on what chemicals are within the water itself.

Q: Will the chemicals in a tropical fish tank react adversely with any fumes given off by a wax melt?

A: No


Marine tanks require different water conditions to cold water and tropical so the setup will be quite different. However, this will largely be the equipment that is needed. Marine fish tanks need optimum nitrate and salinity levels in order to keep the fish alive and healthy which takes a lot of setup and maintenance.

These levels and the bacteria also needed in the tank to maintain the correct environment should in no way be affected by wax melts.

Q: Will the chemicals in a marine fish tank react adversely with any fumes given off by a wax melt?

A: No

What are the Consequences of Burning Wax Melts around Fish?

In the worst of cases fumes or toxins produced by burning wax melts could result in the demise of your marine life. If this were to happen though it would not be instant but over a significant period of time.

However, there is no research or evidence that this would ever be the case. Advice would be to choose your melts carefully and from reputable sellers. In the US, UK, and EU there are standards that must be met, and their manufacturers must adhere to certain regulations. Opt for non-paraffin wax and burn well away from your tank.

Other Effects of Wax Melts on Fish to Consider

It has been reported that the flickers from the tealight have visibly placed fish under undue stress. Whilst this would not always be the case it is worth being aware that the situation could arise.

Should this happen an electric wax burner would soon resolve the issue.

Best Ways to Keep Fish Safe When Using Wax Melts

  • Use melts made from soy wax or beeswax rather than paraffin
  • If your melts are scented, burn them in another room
  • If you are using an electric burner, use it away from your tank

Related Questions

Are Wax Melts Safer than Candles?

Wax melts do not contain a wick, so the soot generated from a burning wick is eliminated.

Research tells us that more candles are made using paraffin wax which, when burned gives off benzene. Benzene is thought to be carcinogenic. Whilst some wax melt companies do still use paraffin wax it is less so than the conventional candle. Be sure to check the ingredients before you buy.

The main safety advantage of a wax melt over a candle is that they can be flameless. By using an electric wax warmer you are removing the very thing which causes millions of dollars worth of property damage in the US each year. The flame!

In our opinion yes, wax melts are safer than candles if used with an electric burner.

What Essential Oils are Toxic to Fish?

There are too many variables of species of fish and number of essential oils to definitively answer this question. A specific essential oil that may help to treat or cure a fungus or illness in one fish may actually be poisonous to another species.

Should you keep different species in the same tank you will always need to cross reference any oils you intend to use with the toxicity to each species. Speak with your vet before adding any kind of essential oils to your tank.