Is Dithiopyr a Carcinogenic? [Explained]

is dithiopyr a carcinogenic

Have you ever heard of dithiopyr? It’s a herbicide used by farmers, landscapers, and gardeners alike to control weeds in lawns and crops. But is it safe for use?

Is dithiopyr a carcinogenic pesticide? No, dithiopyr is not classed as a carcinogen. Back in 2015, dithiopyr was declared a potential human carcinogen pesticide. However, there are no scientific facts to back this up.

Today, I’ll explore the scientific evidence surrounding dithiopyr and discuss whether or not it has cancer-causing potential.

What Is Dithiopyr Used For

Dithiopyr is a pre-emergent herbicide that controls certain weeds like crabgrass, annual bluegrass, foxtail grasses, henbit, common purslane, and wild mustard. 

It is sold under many brand names, including Dimension 2EW and several Scotts products, such as Halts Crabgrass Preventer Plus Lawn Food.

It prevents weed seeds from germinating when applied before they can sprout.

Dithiopyr Toxicity Levels

Regarding its safety as a pesticide, dithiopyr has minimal toxicity to humans when used according to directions. The Environmental Protection Agency (EPA) states it’s “practically non-toxic” with “low toxicity” for birds and mammals.

There have been reports of eye irritation from some people exposed to dithiopyr, but overall it is considered safe for use around people if proper precautions are taken.

Is Dithiopyr a Carcinogenic?

There is no direct evidence that suggests dithiopyr is carcinogenic or causes any other type of cancer in humans or animals.

However, because it belongs to the group of chemicals known as organothiophosphates (OPs), there has been some concern about its potential carcinogenic effects on humans over long periods of exposure because other OPs can cause cancer in laboratory animals.

To date, there are no studies linking dithiopyr to any form of cancer in humans or animals.

Using Dithiopyr Safely

Although dithiopyr is considered safe, I always follow the instructions on the back of the product and take any necessary precautions.

Always wear gloves when dealing with herbicides or pesticides, protective clothing is a good idea too when applying, as well as keep children and pets away from areas you’ve treated until it’s had sufficient time to water in.

Importantly, I’d always recommend wearing a mask when using dithiopyr.

Frequently Asked Questions:

Is dithiopyr safe for humans?

Yes, dithiopyr is safe for humans when used according to the directions on the label. However, it can cause eye irritation in some people, so wearing protective goggles and gloves are recommended when using this herbicide.

Which is better prodiamine or dithiopyr?

It depends on the situation. Prodiamine is a post-emergent herbicide, meaning it kills weeds after they have sprouted, while dithiopyr is a pre-emergent weed preventer that prevents weed seeds from germinating.

How long does dithiopyr last?

Dithiopyr typically lasts 4 months in the soil. It is best applied before weed seeds germinate, which occurs in late spring or early summer, obviously thats climate dependent!


To sum up, dithiopyr is generally considered safe for use around people if proper precautions are taken. 

While there have been some concerns about its potential carcinogenic effects due to its classification as an OP chemical, there is currently no direct scientific evidence suggesting that it causes cancer in humans or animals.

Gardeners should always take care when using any pesticide but can be assured that dithiopyr poses only minimal risk when used correctly according to directions.

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