The Great Debate: Does Carbon Clothing Work?

May 28, 2013 By Ben OBrien

It was a stipulation of dismissal with prejudice. The eight-page legal document submitted in U.S. District Court in Gainesville, Fla., outlined the findings of fact in Pickering v. ALS Enterprises Inc.

This document was the single most important piece of evidence ever submitted in the decade-long debate on the effectiveness of carbon-activated, scent-blocking hunting clothing. September 19, 2012, was a landmark day for everyone in the carbon-activated business, but most of all, for Scent-Lok.

ALS Enterprises, the company behind Scent-Lok, was officially the proud owner of a complete victory in the nine federal lawsuits that challenged the clothing's ability to control human odor. Statements found on the company's ads asserting that the carbon-activated clothing would "eliminate" human odor and could be "reactivated" in a household dryer were at the core of the legal challenge.

But after over five years of litigation, Dennis Pickering and other plaintiffs — including a much-publicized group of hunters from Minnesota who had originally sued ALS — would drop their suit.

Funny how things change. Just a few years prior to the conclusion of this long-standing battle, U.S. District Judge Richard Kyle in Minnesota ruled claims that Scent-Lok clothing will "eliminate" human odors were libelous. That ruling, which was a part of a larger summary judgment that sided with ALS on other points, was a major blow to carbon at the time but was now rear view.

The findings of fact now stated among other things that "carbon is a highly effective odor absorbent" and that after expert testing, "Scent-Lok carbon hunting clothing fabrics blocked 96- to 99-percent of the odor compounds and essentially 100-percent of the surrogate body odor compounds."

The final blow was this statement, "expert testing also found that after drying, or washing and drying, Scent-Lok carbon fabrics continue to be highly effective at blocking odor permeation."

The end of the case meant the plaintiffs would get nothing and all of the pending lawsuits would be dismissed with prejudice.

The Finer Details

Here's something that probably wasn't considered: According to a manufacturing insider, who spoke on the condition of anonymity, carbon fabric used in scent-blocking clothing is, once bonded, on rolls which are not "sealed" during any part of the manufacturing process.

"Once cut, the fabric is then sent to the sewing line. Here the panels of fabric are sewn by hand with sewing machines (not automated) and, typical of any garment, are sent down the sewing line."

After more garment construction, the clothes go through several more packaging and shipping segments. The insider claims that in most cases the clothes aren't protected from outside odors or contaminants. Combine all of that with weeks, months, or even years hanging in your local big box store to be fondled like a doorknob at a doctor's office and you've got one saturated piece of fabric by the time it hits the checkout line. The carbon in the clothing has been absolutely filled with odors.

Often the leader of the battles against his carbon foes, T.R. Michels was and is one of the biggest opponents of carbon clothing to hit the Internet. It's hard to read a forum thread or comment string without turning up a note from the Minnesota-based guide, writer, and avid hunter. Michels was battling carbon clothing well before the courts got involved.

"I've spoken to one of the chemists in England who actually designed the chemical warfare suits that the current crop of activated hunting suits are designed upon. I've also spoken to chemists at 3M here in Minnesota," he says. "They both say that in the application of a hunting suit, it cannot work."

That's the common refrain in this conversation, and Michels' points echoed those levied by the many plaintiffs that took Scent-Lok and others to court.

"[Carbon] cannot continue to hold in any odors after 6 to 8 hours from being reactivated. It also cannot be reactivated (of most odors) below 1,600 degrees (in an oxygen-free environment), which is well above the 160 degrees mandated by law that household dryers can achieve."

But Michels is far from a scientist. His expertise on the subject is secondhand; he's just a perfect example of a passionate, educated hunter fighting for the truth.

Aside from the court's decision — it's clear that the initial boiling point of the particular debate was an exercise in

semantics — Michels is right. There are many other details about carbon clothing that we're still missing. Deer hunters have been presented with the scientific data, the field tests, the empirical evidence, and the expert testimony, but the opposition remains, and, in truth, there are pieces of this puzzle that don't quite fit.

The answer lies somewhere between that ol' boy wearing jeans, suspenders, and a red-and-black wool coat in his stand and the scientist testing odor permeation in a scent-free lab.

In other words, the question every hunter should be asking isn't whether the science is valid or if the advertising is dripping with libelous BS. It's whether deer hunting and garment manufacturing's many great realities match up with the rose-colored marketing glasses many converts are wearing.

New (Old) Kids on the Block

If you were looking for any further proof that carbon isn't the most perfect companion for hunting's major scent-blocking manufacturers, you can find it in a recent change in approach. What's the change? For two major players, it's been evolving beyond carbon-activated technology.

In January, Robinson Outdoors announced a revolutionary new technology they call Trinity. This new synthetic technology has been engineered using a special polymeric resin that the company claims "leapfrogs the odor-adsorption capacity of ScentBlocker's own industry-leading Cold Fusion activated carbon technology."

Robinson is calling this a "maturation" away from a very effective technology into a superior scent-blocking fabric, but challengers are pointing the finger at the manufacturer for moving away from the core of what started their clothing business.

"Carbon was not especially weak as an odor adsorber, as it was and is the most adsorptive natural material generally available," says Scott S. Shultz, CEO of Robinson Outdoor Products. "Today with Trinity technology, we unveil a new benchmark of adsorptive performance with the first-ever synthetic material especially engineered for adsorption of human odor, and it clearly states its superiority in independent laboratory testing."

This new gear comes on the heels of Under Armour's major splash into the scent-blocking pool last year. UA introduced a new line and its own new synthetic technology with an aggressive marketing blitz and a flood of fanfare. Zeolite, a synthetic material structured to accept only human odor molecules, is at the core of their clothing. Of course, UA experts have their opinion on carbon.

"Although carbon does work as an absorber, its biggest weakness is that it fills up over time. In as little as five washes, it is only 50 percent effective and cannot be recharged due to its organic structure," says Koby Fulks, UA's senior hunting marketing manager.

"Carbon also has the weakness of bacteria growth. The bacteria causes odor as they work and multiply€¦. Carbon does not inhibit the growth of bacteria."

Shultz touts Robinson's synthetic challenger as even better, and, more importantly, he says, they offer a superior testing process.

"The comparison between activated carbon and Trinity is as simple as natural material," Schultz continues. "Carbon is derived from anthracite coal, walnut hulls, coconut shells, and lots of similar natural organic materials, and Trinity, a synthetic material that is comprised of a series of complex cross-linked molecular chains of proprietary polymeric resins, which are engineered to possess an extraordinary interior surface of perfectly shaped, highly charged micro-pores. Does that sound like over-the-top rocket science compared to a walnut hull? Well, it really is."

"No one is saying carbon doesn't work," Fulks says. "But if the industrial world is switching to synthetic zeolites instead of carbon, that should tell you something."

Another twist in a story fit for a soap opera. For now, it seems we can let the carbon argument fade away; we've got more groundbreaking science to examine and likely a new challenge for skeptical deer hunters everywhere. Looks like we'll find out soon enough what we've all learned from the great carbon debate. Hunters, start your testing.