How Long Do Mothballs Last Outside? An Instructional Guide

Mothballs, which are typically composed of chemicals such as naphthalene or paradichlorobenzene, are commonly used to repel moths and other pests from stored clothing or other items. When used outdoors, their effectiveness and longevity can be influenced by various factors.

The duration mothballs last outside depends on environmental conditions, such as temperature, humidity, and airflow. Higher temperatures tend to accelerate the evaporation of the active ingredients, shortening their lifespan. Moisture and airflow can also impact their effectiveness.

In general, mothballs placed outdoors may last anywhere from a few weeks to several months. However, it is important to note that their efficacy diminishes over time, and they may need to be replaced periodically to maintain their repellent properties. Additionally, exposure to rain or excessive moisture can significantly reduce their effectiveness.

To ensure the most efficient use of mothballs outside, it is recommended to regularly monitor their condition and replace them when they have significantly diminished in size or potency. Proper storage in sealed containers or bags can also help prolong their lifespan. It is important to follow the instructions provided by the manufacturer for optimal use and disposal of mothballs.

The Lifespan of Mothballs

How Long Do Mothballs Last Outside?

How long a mothball lasts outside depends on how it is used. The usual lifespan of a mothball is about one year under the right conditions. But there are a few factors to take into consideration:

  • The Weather: Mothballs tend to last longer in hotter climates due to their lack of water availability. In places where it is cold or wet, the lifespan may be shorter, especially when exposed to direct sunlight for extended periods of time. 
  • The Number of Mothballs: The more mothballs are used in a given area, the longer they will last outside because there’s not much space to spread out and the air gets trapped which allows for less evaporation. 
  • The Location: If mothballs are placed underneath clothes, then their lifespan typically increases to twice as compared to being left in the open air without any cover.

Depending on those factors, mothballs last anywhere between three to twelve months in the open air.

Is It Legal to Place Mothballs Outside?

No, it is not legal to place mothballs outside.

The reason it is illegal to place mothballs outdoors is that they can accidentally poison pets, wild animals, and even people. Since mothballs contain paradichlorobenzene (PDB), which if ingested, may cause serious health issues such as abdominal pain, nausea, and even severe vomiting!

How Long Does It Take for Mothballs to Stop Smelling?

It really depends on how old the mothballs are and how much of their chemical has been released into your home.

Generally, it takes anywhere from a few days to a week for them to stop emitting fumes that stink up your house. But in some cases, this process can take longer depending on how strong the smell is and how many items you have stored in the same room with them.

While it may be a pain to deal with how long mothballs last outside, once you’re done using them and their fumes have cleared up, your home will feel fresh again! 

The Hazards of Mothballs

Just How Toxic Are Mothballs Really?

As we just mentioned, mothballs can be very toxic. In fact, the chemical found in mothballs, PDB, is used to kill insects and has been determined by the U.S EPA (Environmental Protection Agency) as a possible human carcinogen.

The exact toxicity of how much exposure does it take for someone to become ill from using mothballs outdoors depends on how much of the chemical enters their body.

Should I Put Mothballs In My Yard?

Considering that it is both illegal and dangerous to place mothballs outdoors, you should never put mothballs in your yard. Otherwise, you risk facing a lawsuit.

Should I Use Mothballs Inside My Home?

Even if you put the mothballs inside your home, it’s still not a good idea. Mothballs can cause respiratory problems for those who are exposed to them and they emit toxic fumes that may lead to nausea or vomiting as well as headaches.

Additionally, even though most people use mothballs in enclosed spaces such as attics and garages, they can still enter your home if not properly sealed. In fact, mothballs typically evaporate in one to three months and the fumes become concentrated even more which increases how hazardous it is for people inside a structure where mothballs have been placed.

Furthermore, mothballs are also known for being quite flammable. So it’s also a safety hazard to place them inside your home.

The Right Way of Using Mothballs

What Are the Uses of Mothballs?

By now, you’re probably thinking, “If mothballs are so dangerous, then why do they even exist?” Well, there are several reasons. But mainly, mothballs are used for personal hygiene and for clothing. 

Here are some of their most common uses:

  • Placing them inside closets or drawers to keep them smelling fresh and free of any pests.
  • Using them in a room where someone has died in order to prevent any odor lingering there.
  • Safely storing clothing materials, including wool, cotton, and jeans.

How to Use Mothballs Safely?

As you may have guessed, there’s a safe way to use mothballs indoors. Otherwise, they wouldn’t even exist. 

So how can you use mothballs safely?

It’s pretty simple. Just make sure to store them inside an airtight container that’s non-combustible and keep the container away from any direct sunlight. You can either fill the container with only mothballs for their repugnant-smell-reducing abilities or fill it with mothballs and your clothes that you want to keep protected from moths.

How Can I Get Rid of the Smell of Mothballs?

When you place mothballs inside your home, there’s a chance their smell will fill every nook and cranny of your property. 

In case the smell is overwhelming, here are a few tips to get rid of their odor:

  • Open all the windows and doors.
  • Turn on any fans you have inside if possible.
  • Use an ionizer to control the smell.
  • Use essential oils to freshen up the air inside your home.
  • Steam clean every room, including carpets, furniture fabrics, and drapes. The heat from the steam will help remove some smells that are deeply embedded into the surfaces where the mothballs were placed.
  • Place your clothes that are being protected with mothballs in a dryer to help remove the smell from them.
  • Use baking soda to absorb any mothball-smells lingering inside your home and vacuum it up after 24 hours. 

What Can You Use Instead of Mothballs?

There are plenty of other items that can be used as pest control. Here are a few suggestions:

  • White vinegar is very effective in repelling moths and other pests since they don’t like its smell at all! Plus it’s safe for your family to use.
  • Baking soda is another natural way to get rid of moths. It’s completely safe as it’s not toxic at all if ingested by humans or animals. 
  • Cedar chips can be used to repel moths, ants, mice, and even termites while also neutralizing any unwanted odors in your home.

Frequently Asked Questions

Let’s answer the most frequently asked questions about mothballs.

1. How do you get rid of mothball smell outside?

To get rid of mothball smell outside, follow these steps. First, remove any mothballs present and dispose of them properly. Next, ventilate the area by opening windows and doors to allow fresh air circulation. Use natural odor absorbers like activated charcoal, baking soda, or coffee grounds. Scatter them in bowls or fabric pouches throughout the area to absorb the smell. Additionally, wash any affected surfaces with a mixture of vinegar and water or a mild detergent. Finally, let the area air out for a few days, repeating the process if necessary. Regular cleaning and fresh air should gradually eliminate the mothball smell outdoors.

2. How long does the smell of mothball last outside?

The duration of the smell of mothballs outside can vary depending on several factors. Generally, mothballs release a strong and distinctive odor due to the presence of naphthalene or paradichlorobenzene. In an outdoor environment, the smell may dissipate more quickly compared to indoor settings due to increased ventilation and exposure to natural elements like sunlight and air circulation. However, the exact duration can be influenced by factors such as temperature, humidity, wind, and the number of mothballs used. It’s challenging to provide an exact timeframe, but typically, the smell of mothballs outside might linger for a few days to a couple of weeks before gradually fading away.

3. How long do mothballs last in the attic?

The lifespan of mothballs in an attic can vary depending on several factors. Generally, mothballs can last anywhere from a few weeks to several months in storage. However, in an attic where the temperature and humidity levels can fluctuate, their efficacy may decrease more rapidly. Mothballs gradually vaporize over time, releasing the chemicals that deter moths and other insects. If the attic is well-sealed and has limited air circulation, mothballs may last longer. It is important to note that prolonged exposure to mothballs can be harmful to humans and pets due to the toxic nature of the chemicals. It’s advisable to explore alternative pest control methods or consult a professional for safe and effective solutions.

4. How to get rid of mothball smell from clothes without washing?

To eliminate mothball smell from clothes without washing, there are a few approaches you can try. First, hang the garments outside in fresh air and sunlight for several hours. The combination of sunlight and ventilation can help dissipate the odor. Another option is to place the clothes in a well-ventilated area, such as a closet with an activated charcoal or baking soda odor absorber. Alternatively, you can use fabric fresheners or sprays specifically designed to remove odors, spraying them lightly onto the affected garments. Lastly, consider using steam to refresh the clothes; either with a handheld steamer or by hanging them in the bathroom while taking a hot shower.

5. What are the dangers of using mothballs outside?

Using mothballs outside can pose several dangers. First, mothballs contain toxic chemicals such as naphthalene or paradichlorobenzene, which can be harmful to humans, pets, and wildlife if ingested or inhaled. These chemicals can cause respiratory issues, liver damage, and even cancer in prolonged exposure. Secondly, mothballs can contaminate soil and water sources, leading to environmental pollution. This can harm plants, aquatic life, and disrupt ecosystems. Lastly, mothballs’ strong odor may repel beneficial insects and pollinators, negatively impacting biodiversity. Therefore, it is important to avoid using mothballs outdoors and opt for safer alternatives to protect both human health and the environment.

Conclusion: Mothballs Should Only Be Used Indoors

It’s illegal to use mothballs outside. So you should only use them indoors. Even inside your home, you shouldn’t just put them wherever you want. No, you should ensure that they’re placed inside an airtight container that’s kept away from direct sunlight. That’s the only way to use mothballs safely.

If that sounds like too much of a hassle, then you can substitute mothballs with vinegar, baking soda, or cedar chips.


  • Nathan Collins

    Having spent years working in the landscaping industry, Nathan Collins has cultivated a wealth of knowledge about the natural world. He is committed to helping others appreciate the beauty in their backyards, whether it's through identifying rare rocks and minerals or crafting the perfect landscape.

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