UL backpackers primarily wear Merino wool for odor control. The NASA and the European Space Agency astronauts wear X-Static® instead.

Which is better for odor control? Please provide a link to any scientific research that supports your position?

I found that the SEKRI stuff did nothing for me while wool has.

Brett,

What is the silver thread % in the garment you tested? Some of their garments only use X-Static silver coated threads on the sides. Is the one you tested like this?

The socks that tested best for me have 19% - 30%. I can't tell any difference in the effectiveness in this range. The base wear that tested best for me has 30%. Most vendors’ marketing literature doesn't tell you the silver thread % but it should be listed on the fiber content label inside the garment.

The most relevant scientific literature I've looked at shows that at least 8.6% silver thread content is required for significant odor reduction.



The graphic source is ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, Jan. 1987, p. 93-99 Vol. 31, No. 1
0066-4804/87/010093-07$02.00/0
Copyright © 1987, American Society for Microbiology

Edited by richard295 on 10/28/2009 10:31:03 MDT.

I think it is 3% but it might be 4. I tried one of those high silver count baselayers but the biggest size they had was too small and off in under two hours. If you find some of the high count stuff in a XXL, let me know.

Brett,

The SEKRI only has panels in the sides that are made from X-static. The limited area in combination with the low silver thread % should be factored into the interpretation of your experience.

S3 fabric contains 62% Nylon, 30% Silver Nylon, 8% Spandex; it is available in 2XL from Robinson Outdoors for $49. A size L weighs 9.6 oz. The same garment is frequently available from other sources at a discount. There are many other sources of silver ion technology all using different brand names.



I took the above photo at 60x but the silver % coverage is easily visible to the naked eye when looking at the inside of competitive fabrics.

Edited by richard295 on 10/28/2009 13:12:19 MDT.

It does not look like my SEKRI has any panels but is made out of the same material throughout.

I also have experimented with a Terramar Pioneer crew T shirt that has VisaEndurance silver ions and it works to the degree that it turns my odor from 'sour' to 'musky'
And I have tried out that ScentShield stuff but the XXL is more like a slightly loose L.

Edited by bpeugh on 10/28/2009 13:22:24 MDT.

> most relevant scientific literature I've looked at shows that at least 8.6% silver thread

Richard you rock. You always seem to find great data. Thanks so much. This matches my experience in the field. I didn't know to look for % silver until I found one x-static shirt worked and another didn't. Then I found out one was 4% and the other was 8% I think. Since then I have looked for 8% or better.

I agree with Brett that least one of the SERKI shirts models used ~8% x-static through out the entire fabric... not just the side panels. Sorry to hear they aren't making that anymore.

I have been using synthetic + silver because I have a reaction to wool... but I look forward to seeing if there are good studies between sufficient silver -vs- wool. Thanks for asking this question.

--Mark

Edited by verber on 10/28/2009 15:14:44 MDT.

Brett,

From: Veronica Reid [mailto:veronica.reid@sekri.org]

I'm not sure what you mean. There is a panel in the side that is made from X-static.

Veronica Rosignoli
HALYS Brand Gear/SEKRI

HALYS PCU Long Sleeve Shirt - What is the % of X-Static fibers?

Edited by richard295 on 10/28/2009 15:55:21 MDT.

Not to be rude, but I am looking right at the shirt. It has seems that go right up the sides and continue on the underside of the long sleeves. The only panels are the front, back and arms. I think this was purchased 4 years ago.

Both Brett and Mark have clearly pointed out that a prior version of this base layer was constructed without just an X-Static side panel.

The current version will not be an effective odor blocker. It uses an X-Static side panel only. The panel is comprised of 9025 Polartec PowerDry. This material only uses 3% X-Static fibers. >= 8.6% silver coated fibers, over the entire garment, are needed for optimal odor reduction.

Yeah, I think my non-side panel is 3% and maybe that it is why it is not doing anything for me.

Are there any lighter layers out there that use 8% or above? That ScentShield stuff was like neoprene.

Brett,

To be effective for both moisture transport and warmth maximization ANY base layer needs to hug your skin and that is the only similarity with neoprene. That is the reason Polartec engineered PowerDry and PowerStrecth with stretch. All other Polartec products are not designed as base layers and don’t incorporate stretch.

Warmth is directly proportional to thickness regarding base layers. Conventional underwear varies in thickness from 1.5 to 2.6 mm uncompressed. The thicknesses of base layers designed for high performance outdoor use (plus a cotton sheet for comparison) are as follows:

Edited by richard295 on 10/29/2009 15:31:21 MDT.

Hi Richard. It seems ratio of thickness uncompressed/compressed ratio for the scentblocker is a factor of 2 compared to the other materials. Why is this material so different?

Brett... when you said scentblocker was like neoprene do you mean body hugging, or the lack of air permeability. Close fitting sounds fine, but if it's significantly wind resistant I would find it uninteresting.

It looks like SEKRI must have done at least three generations of shirts. I am sure that my original shirt was 8% through out. Then there is Brett's model that is <=3% throughout. And now there is one that has side panels that are only 4%.

Argh! 1-2 years ago my original SERKI wore out and I picked up a new one thinking I was getting a shirt with identical characteristics. This morning I looked at it closely and discovered that it is like Brett's... 3%, if that. I can barely make out silver fibers in a macro picture and can't really see the silver with an unaided eye. Now the last year makes sense. I didn't know why, but often I was overriding my spreadsheets recommendation to wear the SERKI base, often wearing something lighter and carrying something heavier. I must have subconsciously realized that the shirt isn't working the way it used to and so I was searching for a better option.

+1 to Brett's question: what base layers that are at least 8% silver. [I will add that are silk/featherweight with good air permeability.]

--Mark

Edited by verber on 10/29/2009 16:27:02 MDT.

Mark,

A simple breathe through test on the fabric indicates that it has comparable porosity to the BPL Hoody at its normal stretched size. Its porosity is slightly less than the BPL hoody if the material is not stretched to its normal size. The 8% Spandex, the nylon material, and primarily the weave contribute to the high degree of stretch or compression.

Edited by richard295 on 10/29/2009 16:51:10 MDT.

Thanks Richard. I guess I will take a look at it then. Any data on VisaEndurance? Do you know if they do different concentrations? I requested additional information on their website but haven't heard back yet.

I ask because I have been using a now discontinued tech tee made by Terramar for a couple of years. It has worked well. I recommend Brett to try the Terramar Pioneer material because it's description in the web sounded simular. Brett has had less success. I am wondering if this is likely a body chemistry issue (he's more smelly :-), I am socially inept (I smell and don't know), or if it might a variation in formulation.

--Mark

Mark,

Sorry Mark (smile) - Some characteristics of body odor are specific to the individual, and can be used to identify people, as is often done by dogs. An individual's bodily odor is also influenced by diet, gender, genetics, health, medication, occupation, and mood.

The common odor we humans detect is the anaerobic waste products from the bacteria on the skin. This is what the silver ions eliminate. There are a large number of manufacturers that have unique trade names for basically four categories of products with variable concentrations of silver. X-Static is just one source for silver plated yarns. I was too lazy to analyze all of the alternatives and so just followed the lead of NASA as to what was best. The following grid comparison (Visaendurence Sourced) shows the general characteristics of the four categories:

Well, I was talking about the feel, thick and rubbery as for the ScentShield garment. It felt like it would be more akin to a Cap 4 or more for warmth.

As I said, the VisaEndurance seemed to work to a degree in that is lessened the odor but did not get rid of it. It is better than 3% X-Static and Gladiodor which is better than regular synthetic. The ScentShield stuff may have done the job for me but their biggest size was still to tight and short for me, 6'5" and about 235#s. What I have noticed is that My old R .5, which is made out of Power Dry, actually does quite a bit better for odor control than straight poly Cap 2.

Brett,

Cap4 is the same material as PowerDry. They are both 3.13 mm thick versus 1.60 mm for the mid-weight ScentShield.

Regarding your body odor chemistry, I am a loss to explain what is going on... it doesn't jive with the published science or my experience.

I can't seem to find any manufacturers online that use X-Static in their clothing. I'm interested in trying it out, can someone tell me where I can get shirts made with X-Static?

-Sid

Cabelas makes a baselayer top an bottom with X-Static under their "MTP" Line. I believe the "Tech Weight" would be most suitable for backpacking - I use it as my 3-season sleep wear and emergency base layer if it gets too cold. I'm not sure what percentage of silver it has.