New rubber mulch almost always has a strong rubber smell for 2 to 3 days after installation. After installation, the smell fades. Rubber mulch that has been in place for a long time only smells strongly of rubber during hot weather. As the rubber heats up, it releases gases that carry the distinctive “new tire” smell. So, your rubber mulch may not smell in winter, but it can begin to release odors at the height of summer.
Does Rubber Mulch Smell Ever Go Away?
The strong rubber mulch smell that you will experience after installation will go away within a few days. The freshly ground rubber will produce a rubber or “tire” scent at first, but this won’t last. So, if you just had rubber mulch installed and the smell is bothering you, don’t worry. It will go away soon. Then, the smell will typically only return in hot weather.
- The strong smell of new rubber mulch disappears after 2–3 days.
- Do not worry if your rubber mulch smells strongly at first—this is normal.
- Natural mulches also have a strong smell immediately after installation, so using all-natural mulch won’t solve the problem.
It is common for new mulch to smell strongly, even if it isn’t made of rubber. You may be surprised to find out why wood mulch smells like manure for the first few days after it is spread. However, both rubber and wood mulches lose their strong smell rather quickly. In a week, the smell will disappear almost completely.
Does Rubber Mulch Smell When it Gets Hot?
Heat can cause rubber mulch to release a strong, rubbery smell. This will happen even if the rubber mulch has been in place for months. So, you may want to avoid using rubber mulch near your home if you live in a region with hot summers. That rubbery “new mulch” smell can return during heat waves.
- High temperatures cause rubber mulch to release a strong smell.
- Hot rubber mulch can produce a strong scent even if it was installed a long time ago.
- To prevent this smell, avoid using rubber mulch if you live in an area with hot summers.
- Avoid placing rubber mulch on the south and west sides of your home, which tend to get hotter in the summer.
During cool weather, rubber produces little to no scent. So, rubber mulch is a low-odor choice if you live in a region with brief, cool summers. If you want to avoid an increased rubber smell during the warmer months, do not use rubber mulch on the south and west sides of your home, which typically receive the most sun.
Why Does Rubber Mulch Smell?
Rubber mulch smells because heat causes rubber to release gases. Some of these gases are natural products, since rubber is harvested from trees. Other gases that contribute to the smell of recycled rubber mulch come from chemicals used in the manufacturing process, where the rubber is processed and hardened. So, some of the smell comes from natural aromatic rubber oils, while others come from carbon black and other compounds used in rubber manufacturing.
- Recycled rubber has a unique smell due to a combination of organic compounds and chemicals introduced to the rubber during manufacturing.
- As rubber degrades, it releases natural and chemical gases with distinctive smells.
- A portion of the gases released from rubber come from polycyclic aromatic hydrocarbons introduced during manufacturing.
This scientific study found polycyclic aromatic hydrocarbons (PAHs) in consumer goods made from recycled rubber, such as mulch. These PAHs come from coal, oil, gas, and wood, not the rubber itself. Instead, these chemicals enter rubber during the manufacturing process. They contribute to the smell of rubber mulch.
Does Rubber Mulch Leak Toxins?
Rubber mulch leaks dangerous toxins into the ground and water supply as it breaks down. Researchers at Washington State University warn against using rubber mulch because the toxins in rubber can harm aquatic ecosystems. Many of the compounds in recycled rubber are known carcinogens. As the mulch naturally breaks down, these chemicals are released into the soil and water supply.
- Rubber mulch leaks toxins, including heavy metals and known carcinogens.
- Zinc oxide and other compounds used during rubber manufacturing combine dangerous chemicals with the natural rubber.
- As the rubber mulch decomposes, these toxins are released into your soil and water supply.
Heavy metals, such as zinc, have been scientifically shown to leach into water supplies from recycled rubber mulch. This can have a damaging effect on ecosystems. Although rubber is a natural product, zinc oxide is used during processing to make the rubber more durable. The byproduct of this process is that these potentially dangerous levels of zinc are bonded to the rubber. These chemicals are unlikely to harm you and your family, but can cause harm to other living creatures.
What Can You Use Instead of Rubber Mulch?
Instead of recycled rubber mulch, use an organic mulch made from wood chips, bark, nut hulls, straw, or shredded leaves. Using organic mulches will provide protection against weed growth, insulate the ground, and provide natural fertilizer as the mulch breaks down. Even better, natural mulches don’t contain the toxins found in rubber mulch, so they are safer for the environment.
- Use a natural, toxin-free mulch instead of recycled rubber.
- Bark mulch, dead leaves, straw, wood chips, and nut hulls are all fantastic natural mulches.
- Most natural mulches are less expensive than rubber.
- Natural mulches don’t contain the toxins found in recycled rubber.
You’ll even save money by using a natural mulch instead of rubber. Recycled rubber mulches are often more expensive than natural alternatives. Plus, rubber decomposes, so it isn’t a permanent mulch. If you’re going to have to replenish your mulch regularly anyway, why not use a less expensive, less toxic natural mulch instead?
Does Rubber Mulch Have a Smell?
If you’re familiar with the smell of tires, you may be wondering if rubber mulch has the same scent. Here are the answers:
- Rubber mulch will smell strongly of rubber for the first 2–3 days after installation.
- Hot weather can cause rubber mulch to smell strongly, even if the mulch is old.
- In cool weather, established rubber mulch will release little to no smell.
- The smell of rubber mulch is caused by organic compounds and chemicals used during rubber manufacture.
- Rubber mulch is scientifically proven to leach toxins and heavy metals into nearby water supplies.
- To avoid introducing toxins into the environment, use other types of mulch, such as wood, bark, or shredded leaves.
Although mulch made from recycled tires has a strong smell when it is first installed, this typically fades with time. However, recycled rubber mulch is more expensive and less eco-friendly than natural options, so we do not recommend using it in your yard.