Your Guide to Pesticide Signal Words

If you have used professional pesticides, or you are currently looking for a product to meet your needs, then you have likely come across pesticide signal words without realizing it. In today’s blog, Forestry Distributing goes into detail about what signal words to look for and why they matter. Continue reading to learn more, and order the pest control products you need from Forestry Distributing today.

Where to Find Signal Words

Check pesticide labels to find the signal words required by the Environmental Protection Agency (EPA). They will be printed on the front label in all capital letters. All but the least toxic pesticides will be labeled with a signal word.

What Are Pesticide Signal Words?

Signal words indicate the short-term toxicity of a given pesticide if eaten, inhaled, or touched. The three signal words you will find in use include: CAUTION, WARNING, and DANGER.


This indicates a lower-risk pesticide, which is slightly toxic if eaten, absorbed through the skin, or inhaled. It may also indicate that the pesticide causes slight eye or skin irritation.


This label indicates a moderately toxic substance or warns of the possibility of moderate eye or skin irritation.


This indicates that the pesticide is highly toxic by at least one route of exposure: oral contact, dermal contact, or inhalation. It may also be corrosive and cause irreversible damage to the skin or eyes.


The “POISON” label is used in addition to “DANGER” if the pesticide is highly toxic if eaten, absorbed through the skin, or inhaled. It will be written in red letters on the pesticide label.

For more information on the exact classifications of each signal word, visit our EPA Pesticide Signal Words page.

How Pesticides Are Classified

How do companies know which signal word to use on their product? They use research performed on laboratory animals. Each pesticide is tested for the common routes of exposure: oral contact (eating the product), inhalation (breathing in the product), and dermal contact (spreading the product on the skin), as well as exposure to the eyes.

Each professional pesticide company is required to use the label corresponding to the highest toxicity level of their product, even if it is practically harmless through other routes of exposure. That means that if the pesticide is highly toxic if ingested, for example, it must be labeled with the signal word DANGER even if it poses a very low risk through dermal exposure.

Why Pesticide Signal Words Matter

Signal words are used to signal to the user how much risk each pesticide product poses. With a better understanding of these signal words, you can choose your pesticides based on their toxicity to humans as well as their efficacy against pests. Keep in mind, however, that all pesticides have the potential to be poisonous or otherwise seriously harmful if used incorrectly. Always follow the instructions on the pesticide label.

Find the professional pesticides you need to get the job done here at Forestry Distributing. We offer a broad variety of vegetation management and pest control products, which has made us a leading supplier for the U.S. Forest Service, the U.S. Department of Agriculture, the National Bureau of Land Management, and more. Place your order today, and look for signal words on the pesticide label to stay informed!

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Contech Verbenone vs. Beetleblock® Verbenone

This question reminds me of two kids on the playground arguing my dogs better than yours.

Chem Tica claims their product Beetleblock® verbenone is better than Contech’s verbenone, that it lasts longer and therefore you will only need a single application per season vs. the two applications that Contech recommends with their verbenone product.

Contech formerly PheroTech and Beetleblock® as the registered trademark of Chem Tica manufacture the two leading brands of verbenone pouches currently being sold in North America.

Contech is a Canadian company based in British Columbia in the heart of the Canada’s Mountain Pine beetle epidemic. Chem Tica is located in Sto Domingo, Costa Rica.

The Contech pouch starts out loaded with 7gm of verbenone as the active ingredient the Beetleblock® pouch 6.75gm active ingredient.

The Department of Agriculture USFS has done extensive testing at both its Missoula, MT and Pineville, LA Technology Development Centers of both Contech® brand and Beetleblock® brand verbenone pouches. You can find a link to those USFS elution rate studies here.

At first glance it seems clear the study showed that the Beetleblock® product dispensed 20± days longer. End of story? Beetleblock® is better . . . right?

Let’s look a little deeper. I believe the real question is not how long although that is important. I believe the question we should be asking is how much is enough? Let’s examine the dispensing rate. Beetleblock® dispenses an average 6.75gm ÷ 108 days= .06gm/day, Contech’s verbenone pouch an average 7gm ÷ 75 days= .09gm/day or basically 45% more verbenone per day with the Contech product. From what I’ve seen in the field I believe this is important!

Here is why this is important.

1- If you are in an area hard hit by Pine beetles, studies have shown you will need the higher dispensing rate, in fact its been shown on larger trees you may need two verbenone pouches twice per season to improve your protection odds.

2- Do the math, If you apply your verbenone pouches in April, May or early June count out either 75 or 108 days. Do not leave your trees unprotected in the height of the beetle flight.

3- Consider why the USFS selected Contech verbenone pouches as their primary verbenone supplier for 2010.

My advice, plan on two verbenone applications per season and pass off the Beetleblock® one pouch per season as ridiculous hype.

Keywords: Contech verbenone, Beetleblock® verbenone, Chem Tica, Mountain Pine Beetle, Biopesticide, Organic, USFS, Naturopathic, Verbenone

The author John Vanderhart is a Colorado Dept. of Agriculture licensed Qualified Supervisor and is a regular contributor to Forestry Distributing’s blog. 

ODC Colloidial Chitosan, Panacea or Snake Oil?

Agrihouse Inc the manufacturer of ODC Colloidial Chitosan has been on a marketing crusade promoting their newly EPA approved formulation of Colloidial Chitosan as nothing less than a miraculous, low cost and ecological cure for pine beetle. If you haven’t seen a story in the paper or on TV about this product then you probably live in a cave or out in a forest.

Colloidial Chitosan has been around for a while and has seen many lives including uses as a human diet supplement. In a nut shell or better put, a shrimp shell, yes actually byproduct marine shrimp and other crustaceans shells are ground up, there's some hocus pocus and voi-la, out of a hat or test tube or something comes ODC. I’ve heard if they modified just a few ingredients they’d have Jambalaya.

As a Colorado Department of Ag licensed Qualified Supervisor and having been in the Mountain Pine Beetle treatment and prevention business professionally for going on 8 years I have always been reluctant to promote or endorse a new product until I can touch it, have used it and I can vouch for it personally. So that being said, why has Forestry Distributing picked up Agrihouse’s ODC?

It’s simple, while I would be reluctant to promote ODC alone as a defense against Mountain Pine Beetle I believe it can play an important role in a well conceived Integrated Pest Management “IPM” strategy. At present the tool box of organic measures and biopesticides is limited. Insect pheromones like Verbenone for Mountain Pine beetle and MCH for Douglas-fir beetle are effective but have their limitations. I welcome a product like ODC as just another naturopathic tool to combat these beetles.

By pre-arming drought stressed trees with additional sap, ODC Colloidial Chitosan helps trees naturally combat Pine beetles hydraulically. As the beetles attempt to bore in, sap pours out and hopefully the beetle is entombed and dies. Have you ever seen those pre-historic bugs in amber? Additionally, Agrihouse claims that pine pitch pre-armed with ODC is stickier.

Although the jury is still out as to ODC being able to live up to all the hipe, treating the trees of chemically sensitive individuals, trees in and around schools and playgrounds, organic vegetable gardens, riparian areas and along lakes, ponds and stream banks and other areas not suited for traditional pesticide application now have an additional tool in the fight against Pine beetles.

Keywords: ODC Colloidial Chitosan, Agrihouse, Mountain Pine Beetle, Biopesticide, Organic, Naturopathic, Verbenone, MCH

The author John Vanderhart is a Colorado Dept. of Agriculture licensed Qualified Supervisor and is a regular contributor to Forestry Distributing’s blog.