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How Long Do Mothballs Last Outside? (Quick Answers)

Mothballs mainly consist of naphthalene which gradually turns into fumes and blends with the air in the surroundings if left outside.

So if you are willing to use mothballs to control pests, insects, animals, and birds outside, the first query that will hit you is that how long mothballs are supposed to last if they are used outside of the home. 

Therefore, don’t make any more delays and jump into the precisely explained answers ahead to learn more. 

Can You Put Mothballs Outside?

You cannot put mothballs outside because placing mothballs outside has been announced as an illegal action that shouldn’t be performed. 

The practice of using mothballs is restrained by the US EPA (U.S. Environmental Protection Agency).

And this means mothballs can’ be used outside for any other purpose than the actual cited purposes because they can cause severe harm to not only the wildlife and environment but also humans.

How Long Do Mothballs Last Outside?

If mothballs are kept outside in the open air, they are most likely to last anywhere from 3-6 months. However, note that there isn’t any confirmed exact time that would define how long mothballs are going to last outside because it totally relies on the weather and recent environmental situations. 

How Long Does It Take For Mothballs To Dissolve Outside?

Most probably it will take anywhere between 3 to 6 months for mothballs to dissolve completely in the open air outside. 

But the probable rate at what mothballs are supposed to dissolve entirely relies on the conditions of the outside environment and the temperature and weather of that place where it’s located. 

Precisely to say, mothballs tend to dissolve more quickly if they are kept outside in an area with a high humidity level or very hot weather. Thereby, mothballs in such places may take less than 3 months to dissolve completely and create fumes around the surroundings. 

If mothballs are placed outside in a place with cold temperatures, they are supposed to dissolve lately. So in such a condition, mothballs may or may not dissolve in 6 months. 

However, mothballs will not melt outside if it’s raining, technically because of the chemistry of the elements used in mothballs.

Therefore, even if mothballs got wet in rain, they will not dissolve less than in 3 months, rather they will dissolve between in 3-6 months naturally by turning into fumes. 

Will Mothballs Melt In The Rain?

Mothballs will not melt in the rain as mothballs sublimate. 

To explain in physic’s language, sublimation is a process that transforms the form of an element from a solid state to directly a gaseous state without making it go through the liquid state and without changing the essence of the element. For instance, dry ice (frozen CO2). 

Mothballs are also made following the same theory of sublimation according to physics. As a result, like the dry ice, mothballs also go through a physical conversion from a solid state to directly into a gaseous state without melting upon coming in contact with rainwater.

This means mothballs will vaporize under natural atmospheric coercion and temperature. And this change of mothballs from solid to gas is considered a cool aspect of them as they will not melt in the rain if tossed outside. 

What Happens To Mothballs If They Get Wet?

Although mothballs don’t melt if they get wet, they can turn into an even more worse and potent element in a wet state than the dry mothballs.

And if the reason for wetness is intense such as exposure to the water from any leaking pipe or downpour or high humidity level, either of them is potential to make the mothball odor more strong and sublimation quicker. 

As a result, such heightened potency is likely to put a person who is treating or washing garments in even more danger. 

Why Are Mothballs Bad For Outside? 

In this section, you will be guided through all the potentially harmful facts to learn why it’s considered so bad to use mothballs outside.

Contains Dangerous Chemicals: 

Most mothballs surely do contain either naphthalene or Paradichlorobenzene aka PDB, and not to mention both of the ingredients are highly active. It’s because both of them are fumigants which means that these volatile chemicals will be evaporated while emitting fumes. 

Besides naphthalene is flammable and PDB is also very harmful, and mothballs containing any of these chemicals are highly toxic to be used outside. 

Toxic To Humans (Especially Children): 

As mothballs contain toxic chemicals such as naphthalene or PDB, they are highly toxic to human health, especially if they are consumed accidentally by children. 

Any of these chemicals can cause adverse health conditions that include nausea, vomiting, eye and nose irritation, headache, coughing, lethargy. 

Or even can cause even more lethal conditions such as liver and kidney failure if anyone is exposed to mothballs for extended periods. 

And exposure to naphthalene for an extended period can cause harmful health issues like hemolytic anemia as ingesting naphthalene destroys red blood cells.  

Risky For Kids’ Health: 

Kids tend to put anything in their mouth while exploring their surroundings if mothballs are used outside in the yard, so while playing they easily can assume mothballs as candies and eat them which can risk their overall health very badly.

They also can endure from any of these critical health issues mentioned above.

Harmful To Breathe: 

Using mothballs outside around the house is equally harmful if breathed in because they will emit toxic fumes which for sure will enter the house. And breathing such toxic fumes for a long time can cause breathing difficulties, dizziness, nausea, disorientation. 

Kids and pregnant women are more susceptible to these health issues if they are exposed to mothball fumes and breathing them for an extended period.

Puts Wild Animals’ And Pets’ Lives At Stake: 

Mothballs aren’t any effective and safe animal repellent, rather they put the wild animals’ lives at stake if mothballs are used outside as pest, insect, or animal repellents. Also, it can be proven fatal to pets 

Because wild animals and your pets may assume these mothballs as food and can consume them and the toxic chemicals in mothballs can seriously harm them that they may even require instant veterinary attention. 

Causes Environmental Problems: 

Mothballs contain either PDB or naphthalene, so when mothballs are put outside in the yard as repellent, both the chemicals are likely to get into the ground and most potentially into the groundwater as some chemicals can get washed by rain into sewers and waterways.

And both naphthalene and PDB are poisonous to aquatic creatures, oysters, and many other fishes. 

Besides, if you are using mothballs in your garden and growing veggies at the same time, your crops can absorb these chemicals through the soil around them and these crops are also most likely to contain these chemicals. 

How Do You Spread Mothballs In Your Yard?

A step-by-step guide to spread mothballs in your yard is included below. 

Determine The Exact Place: 

Instead of spreading mothballs all over the yard, determine an exact place or plant beds where you want to put mothballs. And don’t choose any place near a leaky pipe or well or waterbody. 

Spread The Mothballs: 

Do wear gloves first, and then spread mothballs one by one in between the plants in the plant beds. 

Avoid Putting Near The Stem:

Don’t put mothballs near stem. 

Put Mothballs Every 3-6 Months: 

Since mothballs vaporize, spread mothballs every 3-6 months or when they are about to vaporize fully. 

**Note: We strictly don’t recommend spreading mothballs in your yard as it’s harmful to both humans, plants, animals, and the environment. Here this step-by-step guide is added only because many of you out of curiosity want to know the process of spreading mothballs** 

How Long Are Mothballs Effective?

Typically, the effectiveness of mothballs is supposed to last for about 12 months if the mothballs are used by keeping underneath clothes without coming in contact to open air. 

But for most good quality mothballs that are absolutely new and have come in an unopened packet from the manufacturing company will keep maintaining their effectiveness until the expiration day which usually is about 2 years from the day of manufacturing.

However, every mothball manufacturer has a distinct expiration date which always is labeled on the packaging of mothballs to let customers know how long mothballs are going to stay effective. So, it’s always best to check the expiration date to know the exact date of usefulness. 

Besides, bear in mind that the exact time of mothballs’ effectivity depends on the environment and temperature they are being used at. 

Final Thoughts 

Mothballs exposed outside are likely to last for about 3-6 months. But this time period isn’t the precise one because the environmental conditions such as rainy days and temperature such as cold/hot weather outside greatly impact the duration that decides how long mothballs will last outside.