The Same Molecule, Two Legal Statuses: Mothballs Used as a Wildlife Repellent

1. Introduction: a pesticide nobody calls one

Mothballs are sold in grocery stores beside cleaning products. They are a registered pesticide with a legally enforceable label, and that label permits one site of use.

1.1 Written as a caption to a photograph of a label

In an extension publication explaining the point.¹

1.1b And the category is worth naming

This is a consumer pesticide bought by people who do not believe they are buying a pesticide, used by people who have not read a label because it did not occur to them that there would be a legally binding one. That is a different situation from the products our other consumer articles examined, where the buyer knew what they were purchasing and doubted whether it worked.

1.2 What this article argues

That the common misuse cannot work for mechanical reasons, that it delivers the exposure to the wrong people, and that the reasoning behind it is defensible because the same active is sold legally for that purpose in a different package. Sections 10, 13 and 15 are the case.

2. What they contain

Mothballs are registered as pesticides because they contain high concentrations of one of two active ingredients, naphthalene or paradichlorobenzene, with more than 30 products registered with the US EPA that contain paradichlorobenzene and more than a dozen products that contain naphthalene.²

2.0b And the concentrations are high

The registration exists because the products contain high concentrations of one active, which is the opposite of the dilute formulations most consumer pesticides arrive in.²

A householder handling a box of mothballs is handling a more concentrated pesticide than one handling a ready-to-use spray, which is not how either feels. That observation is ours.

2.1 Sold in several physical forms

Cakes, crystals, tablets, bars and flakes.³

2.1b Which makes the product physically diverse and legally identical

A crystal, a flake and a ball behave differently in the hand and sublime at different rates by surface area, while sitting under the same registration and the same label.³

2.2 And registered because of the claim

They are sold with a very specific claim that they repel a pest, and because a pest repellent or control claim is made, the regulator requires registration and creation of a product use label.¹

3. How they work

Through a process called sublimation, mothballs slowly convert from a solid into a gas.² Both chemicals are fumigants, meaning their volatile chemicals vaporise at lower temperatures such as room temperature.³

3.0b Which makes the solid a reservoir rather than a dose

The quantity placed is not the quantity delivered. What matters is the rate at which the solid converts and the volume that receives the gas, so two identical handfuls in an airtight bag and an open attic produce entirely different exposures to everything in range.²

3.1 And the vapour is a deterrent rather than a contact poison

One account describes it as not a toxin that kills on contact but a scent irritant that makes the treated area unpleasant or disorienting for certain insects and rodents.⁶

4. Which makes the container part of the method

Our observation, and it is the distinction the whole article turns on.

Mothballs are designed to work in sealed enclosed spaces such as a cedar chest or garment bag, where the vapour can build up to a level that affects pests.⁶

4.0b Which is why the instruction reads as two instructions at once

Extension guidance gives the container requirement both as protection, preventing fumes reaching living space, and as function, allowing the vapours to build. The same sentence is a safety warning and an efficacy note.¹

4.1 The enclosure is not a safety measure bolted on

It is the thing that produces the working concentration, and without it there is no dose.

4.2 Which is unusual among consumer pesticides

A spray works where it lands. A bait works where it is eaten. This one works only inside a volume small enough for the vapour to accumulate.

5. And the label says so

In the terms extension guidance quotes.

Mothball containers typically direct the user to place mothballs in a tightly closed container that will prevent the pesticide fumes from accumulating in living spaces where people and pets can inhale them and become ill, and the airtight container also allows the vapours to do their work.¹

5.0b Note which two things the container does

It keeps the vapour in, which is the efficacy function, and it keeps the vapour away from people, which is the safety function. A single physical requirement discharges both, and removing it defeats both at once.¹

5.1 With one specific prohibition

Mothballs must be used in an airtight space such as an airtight garment bag or other container labelled as airtight, and never in an open closet or plastic garbage bag.³

6. The label is the law

Stated directly by the same source.

As with any pesticide, the label is the law. The label language is not simply a set of directions. Rather, they are requirements that are legally enforceable.²

6.0b And the enforcement route is a complaint

Any use not directly stated on the label is illegal and can be reported by others to the regulator, which makes a neighbour the practical enforcement mechanism for a garden application.⁵

6.1 Which our earlier article set out in general

On the label as a binding instrument. This is the clearest consumer-facing instance of it we have found, because the restriction is to a single site rather than to a rate or a method.

7. What they are actually used for

An extension specialist: Unfortunately, mothballs are used in these locations to control pests other than clothes moths, including squirrels, skunks, deer, mice, rats, dogs, cats, raccoons, moles, snakes, pigeons and a variety of other animals. Any such use is illegal and can be harmful to human health.³

7.0b The locations follow from the belief

Attics, crawlspaces, garden beds and foundation perimeters are where the animals in that list are believed to be, which is why the product ends up in every kind of space except the one it is labelled for.⁸

7.1 With one example named

A relatively common mistake is placing mothballs in an attic to repel squirrels.³

8. Twelve species, no moths

Our count of that list.

Every animal named is a vertebrate, and the product is registered as an insecticide against a specific group of moths.¹³

8.0b And the range of body sizes is telling

A deer and a mouse differ by three orders of magnitude in mass, and no dose-based reasoning produces a single product effective against both. A list spanning that range is a list of animals somebody wants gone rather than a list of targets.³

8.1 Two of them are the householder's own pets

Dogs and cats appear in a list of intended targets.³

8.2 Which suggests the product is understood as a general aversive

Something unpleasant that makes animals go away, rather than as a compound with a target and a dose.

That reading is ours and §15 says why it is not a stupid one.

9. And it is investigated as misuse

By at least one state regulator.

A state agriculture department frequently receives complaints and investigates the misuse of mothballs, with most misuse involving outdoor placement on the mistaken idea that the pesticide will repel snakes and other nuisance wildlife.²

9.0b And outdoor placement is the dominant form

Most misuse involves putting the product outside, which is the use most certain to fail on the mechanism in §3 and least likely to expose the household in the way §12 describes. The commonest version is the most futile and the least dangerous.²

9.1 Frequently is the operative word

This is a routine enforcement matter rather than an occasional one.²

10. Why it cannot work

Following from §4.

Outdoor use is ineffective because the vapour disperses too quickly in open air.⁶

10.0b And it is the same argument our fumigation article made

That the effective quantity is concentration multiplied by time, and that a structure which cannot be sealed cannot hold either. A garment bag is the smallest possible version of that requirement and an attic is a failure of it.

10.1 Which is not a claim about the animal

It is a claim about the concentration, and it holds regardless of which species is being aimed at.

10.2 So the twelve species in §7 are beside the point

The method fails before any question of animal response arises.

That is ours.

11. Even indoors

Where some enclosure exists.

One account states that even indoors the concentration never gets high enough to bother a mouse, and that mice can simply avoid the immediate area of the mothball and continue using other entry points.⁷

11.0b And the mechanism suits an enclosed garment bag exactly

A larva in a woollen coat inside a sealed bag cannot leave the treated volume. Every animal in §7 can, which is the difference between the labelled use and all the others in one sentence.

11.0c And avoidance is cheap for the animal

Moving a metre is not a cost worth weighing against a food source or a nest site, which is what distinguishes a repellent from a barrier.

11.1 Which our house mouse article explains

An animal with many feeding sites and a home range of a few metres has alternatives available within its territory, so a locally unpleasant patch is a detour rather than an exclusion.

12. Where the vapour goes instead

Loose mothballs should not be placed in attics or crawlspaces without containment, because fumes travel through walls and HVAC systems into living spaces.⁶

12.0b Which means detection is not reassurance

Smelling mothballs indoors establishes that vapour has arrived, and says nothing about whether the concentration is trivial or substantial, since the nose responds well below any level of concern.³

12.1 And the odour threshold is very low

Once vapours enter the home, their odour can be detected at a few parts per billion in the air.³

13. Which inverts the exposure

Our conclusion from §§10 and 12.

The animal in the attic experiences a concentration too low to deter it. The family below experiences a concentration high enough to smell continuously.

13.0b And the direction of airflow makes it worse

Warm air rises through a heated building and is replaced from below, so a void above the living space is connected to it by a pathway that operates continuously through a heating season.

That is our reasoning and it is the mechanism behind the sourced observation that fumes travel through walls and ducts.⁶

13.1 Because the two spaces differ in ventilation and volume

An attic is large, draughty and connected to outside. A bedroom is smaller, warmer and on the receiving end of whatever moves through the structure.

13.1b And the timescale differs too

An animal passing through an attic is exposed for minutes. A household below it is exposed for as long as the material lasts, which for a sublimating solid is weeks to months depending on temperature.²

13.2 So the product is delivering its dose to the wrong occupants

Which is the strongest single reason not to do it, and it does not depend on any disputed toxicology.

14. The paradox

Some snake and wildlife repellents available at retail stores do contain naphthalene; however, mothball products are not approved for such use, and that practice is illegal.²

14.0b And the retail settings overlap

Both are available at ordinary retail, which is where the comparison in §15 actually happens.²

14.1 With the difference named

Another extension source notes that wildlife deterrent products containing naphthalene are labelled for outdoor use to repel wildlife, and that the formulation and strength is different.⁵

15. Why the mistake is reasonable

And we think this is the most important paragraph in the article.

A householder standing in a hardware store sees a product labelled for repelling wildlife outdoors whose active ingredient is naphthalene. They then see a much cheaper product whose active ingredient is also naphthalene. Concluding that the second will do the same job is an inference about chemistry, and the chemistry supports it.

15.0b And nothing at the point of sale corrects it

The two products sit in different aisles of the same shop, each with an ingredient panel, each legally sold, with no indication that one has been assessed for the use the buyer has in mind and the other has not.

15.1 What does not support it is the law

Which attaches to the registered product and its label rather than to the molecule.²

15.2 And the formulation difference is real but invisible

Strength and formulation differ, and neither is apparent to somebody comparing two ingredient panels naming the same compound.⁵

16. Legality attaches to the product

Stated as the general principle.

Any use of a pesticide that is not directly stated on the label is illegal.⁵

16.0b And the principle has a name in the trade

Off-label use, which for a licensed applicator is a disciplinary matter with a defined process behind it, and for a householder is a phrase they have never encountered.

16.1 Which is coherent regulation and poor communication

Coherent because a registration is an assessment of a particular formulation at a particular rate for a particular use, and poor because nothing on the shelf conveys that the same chemical is being assessed twice to different conclusions.

That is ours.

16.1b Which is a general fact about how pesticides are approved

Two products sharing an active ingredient are two registrations, assessed separately, and neither approval says anything about the other.

16.2 And our efficacy data article supplies the reason

Registration decisions are made on submitted data about a product, not about an active ingredient in the abstract, which is why two products sharing an active can hold different approvals.

17. And the legal version does not work either

Which completes the picture.

The same source describing outdoor-labelled naphthalene wildlife deterrents calls them largely ineffective.⁵

17.0b Which we report at the strength the source gives it

Largely ineffective is an extension blog's characterisation rather than a trial result, and we found no efficacy data for outdoor naphthalene wildlife repellents in either direction.⁵

17.1 So the choice is between an illegal method that fails and a legal one that fails

Which is the situation our article on minimum risk exemption products described in a different category.

17.1b Which leaves nothing in the category to recommend

An article that concluded the labelled product was fine and the misuse was not would end with a purchase to make. This one ends with a category to leave alone, which is a less satisfying answer and appears to be the correct one.

17.2 And it explains the persistence of the practice

A householder who tries the legal product, sees nothing, and switches to the cheaper one has learned that the legal route did not help, which is true.

18. The toxicology

Briefly, because it is the reason any of this matters.

Naphthalene has been associated with adverse health effects such as headache, nausea, dizziness and difficulty breathing, with paradichlorobenzene also a potential hazard although typically less than naphthalene.³

18.0b And the comparison between the two actives is relative

Typically less than naphthalene is how the second compound is described, which ranks the two without establishing that either is safe at the exposures this article concerns.³

18.1 With a metabolic step

When naphthalene gas is inhaled, the body breaks it down into other chemicals that react with cells in the body and damage tissues.⁴

18.2 Which is the same structure as our pro-insecticide article

Where the parent compound was not the agent and activation produced the active form. Here the activation is happening in the person.

19. The susceptibility that matters

And it is a common one.

Exposure can cause haemolytic anaemia, particularly in people with a deficiency in glucose-6-phosphate dehydrogenase.⁹

19.1 Which is among the commoner enzyme deficiencies worldwide

We state that from general knowledge and did not source it, and the point is that the susceptible group is not small or unusual.

19.1b And the route of concern differs by scenario

The classic cases in the literature involve ingestion by children or exposure of infants through treated clothing and bedding. The misuse described here produces continuous low-level inhalation instead, which is a different exposure pattern from the one the toxicology was mostly built on.⁴

We raise that as a question rather than a finding, since we did not establish what the inhalation literature says about chronic low concentrations.

19.2 And the exposed party may not know

Which distinguishes this from hazards a person can choose to avoid.

20. A paper title worth reading twice

Found in a regulator-affiliated information centre's reference list.

A 1995 paediatric research abstract is titled: naphthalene induced acute haemolytic anaemia in children with glucose-6-phosphate-dehydrogenase deficiency, naphthalene has no legitimate place on the market as a moth repellent.⁴

20.0b And the population it concerns is children

Which is the group most likely to encounter the material by ingestion, and the group in whom the enzyme deficiency is typically first identified.⁴

20.1 A policy conclusion inside a title

Which is unusual, and which we record because it is a clinician's judgement about a product still on sale thirty years later.⁴

20.2 We have not read the abstract

Only the citation, and a title is not an argument.

21. The second active ingredient

Paradichlorobenzene, which is the commoner of the two by registered product count.²

Effects reported include abdominal pain, vomiting, lethargy and trembling, with repeated or large doses leading to liver and kidney damage, and chronic exposure linked to anaemia in animals.⁸ Its vapours can also inflame eyes and nasal cavities and cause a burning sensation on handling.⁵

21.1 And it is the one most people are actually using

Given that it appears on more than twice as many registered products, the compound in a given box is more likely to be the second than the first, which is not something a purchaser choosing by price or smell would know.²

22. Which people meet in another form entirely

And this is worth knowing.

Paradichlorobenzene is also found in deodorant blocks made for trash cans and toilets.²

22.0b With the products serving opposite purposes

A urinal block is bought to put a smell into a room. A mothball is bought to keep insects out of a container, and the smell is a side effect its label treats as something to be prevented from reaching living space.¹²

22.1 So the same compound is an air freshener and a pesticide

Which does more to normalise it than any labelling could counteract.

22.2 And it is our treated article exemption question in a new place

That article examined where a product claim turns an article into a regulated biocide. Here one compound sits on both sides of a comparable line, and the consumer meets the unregulated-feeling version routinely.

23. The instruction not to mix them

Given plainly and without explanation.

Never mix these two types of mothballs.³ The two should not be mixed in the same storage space.⁶

23.0b The instruction appears in two independent sources

One an extension specialist quoted in a university release, the other a trade page, phrased slightly differently and pointing the same way.³⁶

23.1 We could not find the reason stated

Neither source gives one, and we will not guess at the chemistry.

23.2 But it bears on the misuse pattern

Somebody buying whatever is cheapest on successive occasions, and adding it to the same attic, is doing the thing both sources prohibit without ever seeing the instruction.

24. What this has in common with our other label articles

Three of them.

Our article on the label as a legally binding instrument established the principle. Our article on application categories found a regulators' association conceding that most applicators read one section of a label. This adds the consumer case, where the reader is not a licensed applicator at all.

24.0b With one structural similarity across all three

In each case the legal weight sits on a document that the person bound by it has limited reason to read closely, and in each case the binding part is not the part the reader treats as the instruction.

24.1 And the enforcement position is different

A contractor operating off-label risks a licence. A householder scattering mothballs in a garden risks a complaint that a regulator may or may not receive.²

25. And with our consumer products article

Which assessed household pest products and found the efficacy evidence thin.

This is a sharper case, because the product does work as labelled and fails only in the use everybody puts it to.

25.0b And the evidence position is unusually clear for once

For most consumer products this journal has examined, the problem is absent evidence. Here the mechanism is understood, the labelled use is supported, and the disputed use fails for a reason that can be stated in one sentence.

25.1 Which is a different failure from the ones that article described

Not a product that does not work, but a working product used outside the conditions its mechanism requires.

26. What we would tell a client

Three things.

It is a fumigant and needs a sealed container. Without one there is no concentration and no effect.⁶

In an attic it treats your bedroom. Section 12.⁶

And the outdoor products with the same ingredient are described as largely ineffective too.⁵

26.1 And one question we would ask first

Whether any have already been placed, and where, because the answer changes what is being smelled in the house and may explain a complaint that has nothing to do with the animal.

27. Our own position

The disclosure.

We are asked about mothballs regularly, usually after they have been placed, and an article telling people a cheap product does not work is an article that recommends a paid alternative. Sections 10 and 12 are sourced and would hold whoever wrote them.

27.0b And the advice costs us nothing to give

Telling somebody their mothballs are not working does not sell a treatment by itself, since the animal problem that prompted them is still there and was always going to need addressing on its own terms.

27.1 And we have removed them from crawlspaces

Which is a disposal question we have never treated as one, since the material is a registered pesticide applied off-label and not ordinary rubbish.

28. The Manitoba position

28.1 The registration is Canadian

Everything above concerns American product counts and an American regulator, and the label principle in §6 is the same here, as our own article on that subject set out.

28.1b And the retail situation may differ

Whether outdoor-labelled naphthalene wildlife repellents are sold in this country at all is something we did not establish, and if they are not, the paradox in §14 may not arise here in the same form.

28.2 What we could not find

Canadian registered product counts for either active, any provincial record of mothball misuse complaints, and any Canadian equivalent of the extension guidance quoted throughout.

28.3 And a climate note

Sublimation rate rises with temperature, so an unheated crawlspace in winter and an attic in July are not the same application, which is our inference from §3 rather than anything a source states.³

29. Limitations and open questions

Four sources are commercial. Two content-site articles and two pest control company pages, used for mechanism and for toxicology summaries rather than for the regulatory core.⁶⁷⁸⁹

The toxicology is entirely secondhand. We have fact sheet summaries and a reference list, not the studies, and §§18 to 21 should be read as a list of reported effects rather than as an assessment.⁴

The key regulatory claim rests on two related extension publications. The same author and office produced both versions of the source establishing §§14 and 16, so the same-active paradox has one origin rather than two.¹²

That is the most important limitation because §15 is the article's central argument and depends on there genuinely being outdoor-labelled naphthalene products, which we did not verify against any register.

We have no prevalence figure. Frequently and relatively common are the terms available, and no source gives a number of complaints, a proportion of households, or any measurement of how often this happens.²³

And no exposure measurement. The travel of vapour from an attic into living space is asserted by a trade source and is consistent with the odour threshold figure, and we found no study measuring indoor concentrations after this kind of misuse.³⁶

Sections 4, 8, 10.2, 13, 15, 16.1, 22.1, 23.2 and 28.3 are our reasoning. The container-as-method framing, the count of the species list, the inverted exposure argument, the account of why the mistake is reasonable and the observation about the compound's other retail life are ours rather than sourced positions.

30. Conclusion

Mothballs are registered pesticides, sold in grocery stores, containing naphthalene or paradichlorobenzene, and they work by sublimation: the solid becomes a gas and the gas is the active.² That makes a sealed container the method rather than a precaution, because without enclosure the vapour never reaches a concentration that does anything, and extension guidance records that the label names an airtight container as the only approved site of use.¹⁶ In practice the product is used against squirrels, skunks, deer, mice, rats, dogs, cats, raccoons, moles, snakes, pigeons and other animals, a list of twelve vertebrates containing no moths, and any such use is illegal.³

It also cannot work. Outdoors the vapour disperses too quickly; indoors the concentration never reaches a level that troubles a mouse, which simply uses a different route through its territory.⁶⁷ Meanwhile the fumes travel from an attic or crawlspace through walls and ducts into living space, where the odour is detectable at a few parts per billion.³⁶ So the exposure is inverted: too little for the animal it was aimed at, continuous for the household below. That objection needs no disputed toxicology, though the toxicology exists, including haemolytic anaemia in people with a common enzyme deficiency and a 1995 paper whose title states that naphthalene has no legitimate place on the market as a moth repellent.⁴⁹

What makes this more than a story about people ignoring instructions is that the inference behind it is sound. Some retail wildlife repellents do contain naphthalene and are labelled for outdoor use; the formulation and strength differ, and the difference is invisible to anybody comparing two ingredient panels naming the same compound.²⁵ Legality attaches to the registered product, because that is what was assessed, and the public reasons about the chemical, because that is what is printed. And the legally labelled outdoor version is itself described as largely ineffective, which means the honest advice is not to buy the correct product instead, but that nothing in this category is going to move the animal.⁵

References

1. Extension publication on mothballs and their regulation, issued by a university agricultural extension service and read as its full text. Source for the caption stating that the label specifies airtight container as the only approved site for use; for the explanation that mothballs are sold with a specific claim that they repel a pest and that because a pest repellent or control claim is made the regulator requires registration and creation of a product use label; for the description of mothballs, moth flakes, crystals and bars as insecticides formulated as solids; for the instruction that mothball containers typically direct the user to place them in a tightly closed container that will prevent fumes accumulating in living spaces where people and pets can inhale them and become ill, while also allowing the vapours to work; and for the statement that some snake and wildlife repellents available at retail stores do contain naphthalene, that mothball products are not approved for such use, and that this practice is illegal. https://edis.ifas.ufl.edu/publication/PI289/pdf
2. Online version of the same extension publication, from the same office and author, read as a web page. We flag that this and the reference above are two presentations of one document rather than independent sources. Source for the statement that mothballs are registered as pesticides because they contain high concentrations of one of two active ingredients, naphthalene or paradichlorobenzene, with more than 30 products registered containing the second and more than a dozen containing the first; for the note that paradichlorobenzene is also found in deodorant blocks made for trash cans and toilets; for the description of sublimation, by which mothballs slowly convert from a solid into a gas; for the statement that the label is the law, that label language is not simply a set of directions but legally enforceable requirements, and that using mothballs in a way not specified by the label is not only illegal but can harm people, pets or the environment; and for the report that a state agriculture department frequently receives complaints and investigates the misuse of mothballs, with most misuse involving outdoor placement on the mistaken idea that the product will repel snakes and other nuisance wildlife. https://ask.ifas.ufl.edu/publication/PI289
3. University newsroom article on mothballs as a pesticide, quoting a named extension specialist. Institutional press material carrying direct quotation. Source for the statement that mothballs come in cakes, crystals, tablets, bars and flakes and contain either naphthalene or paradichlorobenzene; for the instruction never to mix the two types; for the statement that both chemicals are fumigants whose volatile chemicals vaporise at lower temperatures such as room temperature; for the account that naphthalene has been associated with headache, nausea, dizziness and difficulty breathing and that paradichlorobenzene is also a potential hazard though typically less than naphthalene; for the requirement that mothballs be used in an airtight space such as an airtight garment bag or other container labelled as airtight and never in an open closet or plastic garbage bag; for the statement that once vapours enter the home their odour can be detected at a few parts per billion in the air; and for the quoted observation that mothballs are used to control pests other than clothes moths including squirrels, skunks, deer, mice, rats, dogs, cats, raccoons, moles, snakes, pigeons and a variety of other animals, that any such use is illegal and can be harmful to human health, and that a relatively common mistake is placing mothballs in an attic to repel squirrels. https://news.oregonstate.edu/news/mothballs-are-pesticide-and-should-be-used-care
4. Naphthalene general fact sheet published by a pesticide information centre operated in cooperation with a federal regulator. Read as a page and reference list rather than for its full toxicological text. Source for the statement that when naphthalene gas is inhaled the body breaks it down into other chemicals that react with cells and damage tissues; and for the existence, in its cited literature, of a 1995 paediatric research item whose title states that naphthalene induced acute haemolytic anaemia in children with glucose-6-phosphate-dehydrogenase deficiency and that naphthalene has no legitimate place on the market as a moth repellent, of a 1978 occupational medicine report of aplastic anaemia following exposure to paradichlorobenzene and naphthalene, and of a two-year whole-body inhalation carcinogenicity study of naphthalene vapours in rats together with a national toxicology programme report on the same compound in mice. https://npic.orst.edu/factsheets/naphgen.html
5. County extension blog post on the misuse of mothballs, published by the same university extension system. Institutional but informal material. Source for the statement that wildlife deterrent products containing naphthalene and labelled for outdoor use to repel wildlife exist, that these are largely ineffective, and that the formulation and strength is different from mothball products; for the general principle that any use of a pesticide not directly stated on the label is illegal and can be reported to the regulator; for the account that naphthalene vapour in enclosed spaces can cause nausea, headaches, dizziness and vomiting, with further effects if ingested by children or pets, and that paradichlorobenzene has similar effects while its vapours can also inflame eyes and nasal cavities and cause a burning sensation when handled, with additional liver and kidney risk in pets; and for the note that health effects on wildlife are mostly unknown while both actives are known to potentially harm fish. https://blogs.ifas.ufl.edu/clayco/?p=625
6. Article on whether mothballs can be used for pest control, published by a pest control company. Trade marketing material, cited as attributed material. Source for the description of both compounds releasing a strong vapour as they slowly dissolve, with that vapour repelling pests as a scent irritant rather than a contact toxin; for the statement that mothballs are designed to work in sealed enclosed spaces such as a cedar chest or garment bag where the vapour can build up to a level that affects pests; for the instruction not to place loose mothballs in attics or crawlspaces without containment because fumes travel through walls and heating and ventilation systems into living spaces; for the statement that using mothballs outdoors to repel pests or wildlife is an off-label use violating federal pesticide regulations and that outdoor use is also ineffective because the vapour disperses too quickly in open air; and for the note that the two active ingredients should not be mixed in the same storage space, with naphthalene described as the older formulation with a stronger odour and more acutely toxic. https://www.anytimepestelimination.com/blog/mothballs-pest-control
7. Commercial content article on using mothballs for mice. Content-site material of uncertain editorial standard, cited as attributed material. Source for the statement that mothballs are registered pesticide products carrying a legally binding label specifying use in enclosed containers for moth control only, so that tossing them in a yard, attic or crawlspace to repel mice violates federal law; for the statement that even indoors the concentration never gets high enough to bother a mouse and that mice can simply avoid the immediate area and continue using other entry points; and for its account, attributed to a veterinary reference, that pets can be poisoned by eating mothballs, inhaling fumes or absorbing the chemicals through skin, with naphthalene exposure progressing from vomiting and loss of appetite to red blood cell breakdown. https://scienceinsights.org/how-to-use-mothballs-for-mice-and-why-you-shouldnt/
8. Commercial content article on mothball toxicity. Content-site material of uncertain editorial standard, cited as attributed material. Source for the account that paradichlorobenzene exposure in pets primarily causes abdominal pain, vomiting, lethargy and trembling, with repeated or large doses leading to liver and kidney damage and chronic exposure linked to anaemia in animals; and for the statement that labels specify use only in airtight containers with clothing while in practice people use them in ways that dramatically increase toxic exposure, with scattering in attics, basements or crawlspaces to repel mice, snakes or squirrels both illegal and ineffective. https://scienceinsights.org/are-mothballs-toxic-health-risks-and-safer-options/
9. Article on mothballs in pest control and odour management, published by a pest control company. Trade marketing material, cited as attributed material. Source for the summary that exposure can cause headaches, nausea, dizziness, possible long-term cancer risks and haemolytic anaemia, particularly in people with a deficiency in glucose-6-phosphate dehydrogenase; for the statement that naphthalene is listed as a carcinogen by a named state authority; and for the listing of alternatives including dry cleaning, freezing, pheromone traps, camphor and red cedar. https://www.purcorpest.com/blog/mothballs/