At RootX, we get the opportunity to speak to many of you throughout the day about chemical root control and how it has, or can, help your situation.  We often get questions regarding the various chemical root control products on the market, and how they compare.  I’ll try to give some basic information on the most common chemicals out there.

Let’s first look at the goal of chemical root control. 

Chemical herbicides work by destroying the root tissue.  They are non-selective, which means that they kill whatever they can come in contact with.  The dead roots will then decay naturally and be washed away by the flow of the line.  Some chemical herbicides that we discuss will help to prevent re-growth.

Root control chemicals can be applied in several different ways.  The simplest way is to pour the herbicide into an upstream manhole and have the flow of the line carry the chemical to the roots.  Herbicides can also be sprayed throughout the line with a jetter hose, or by using specialized foaming equipment.  And since chemical root control can only kill what it comes in contact with, you’ll need to use a method that gets the herbicide to the roots.

Chemical root control is effective, and compared to mechanical methods, the results last longer.  That means that chemical treatments are needed less frequently, which saves both time and money over cutting.  Plus, chemical root control is less damaging to pipe materials then hydraulic cutters.

All root control chemicals must be EPA accepted and labeled for use in sewers and storm lines. The EPA restricts the use of some chemicals due to environmental hazards. We’ll get into some of those in greater detail as we look at some of the common root control chemicals.

Copper Sulfate usually comes in the form of blue crystals that are poured directly into the flow of the line.  It’s both economical and easy to apply.  However since it’s carried with the flow of the line it doesn’t always reach all the roots in the pipe.  Copper Sulfate also leaves no residual effect to prevent roots from growing back.  And copper sulfate is very toxic to aquatic organisms.

Based on the NFPA 704 standard for identifying hazardous materials, copper sulfate has a hazard rating of 3, 0, and 1. Three is the next most-hazardous rating on the blue health scale. It means short exposure could cause serious temporary or residual injury. Zero on the red flammability scale means it will not burn. One on the yellow reactivity scale means it is normally stable, but can become unstable at elevated temperatures and pressures.

Metam Sodium is applied using specialized foaming equipment so the foam is carrying the herbicide to the top of the pipe.  Metam Sodium herbicides were the original foaming root control products, and they kill roots that they come in contact with.  However, because of its toxicity, you need to be very careful when handling metam sodium.  It’s classified as a restricted use herbicide by the EPA, so you’ll need to have a license to both purchase and apply the product.

Based on the NFPA 704 standard, metam sodium has a hazard rating of 2, 1 and 0. Two on the blue health scale means intense or continued, but not chronic, exposure could cause temporary incapacitation or possible residual injury. One on the red flammability scale means it must be pre-heated before ignition can occur. Zero on the yellow reactivity scale means it is normally stable, even when exposed to fire, and it is not reactive with water.

Although Sodium Hydroxide isn’t a true herbicide, it’s often used to clear pipes.  It generates a heat on contact with organic matter, oxidizing and decomposing obstructions.  Like copper sulfate, sodium hydroxide is carried with the flow of the line.  So it doesn’t always reach the roots at the top of the pipe.  Sodium hydroxide also has no residual effect that helps to prevent re-growth.  Plus, because of its highly caustic nature, sodium hydroxide needs to be handled with extreme care.

Sodium hydroxide has the same NFPA 704 hazard ratings as copper sulfate.

Diquat Dibromide is also a foaming root control chemical so it reaches the roots at the top of the pipe.  It’s also classified as a general use herbicide by the EPA so it can be used in most applications.  As a desiccant, Diquat kills roots by drying them out.  And it’s non-selective so it kills the roots it comes in contact with.  Diquat does have several limitations however.  It relies on the photosynthesis process for optimal effectiveness.  It also becomes inactive in organic matter, and has no long-term residual effect to help stunt new root growth.

Diquat dibromide has a hazard rating of 2, 1 and 0 according to the NFPA 704 standard. These are identical to the ratings for metam sodium.

Dichlobenil is the active ingredient in RootX.  It foams on contact with water so it fills the pipe with foam.  It can be poured directly into a line, or applied using a jetter.  The EPA has classified Dichlobenil as a