Anti-static mat smell

[RoGeorge]

Just received an order for an anti-static mat bought from Aliexpress. It has 2 layers, the material seems to be rubber.
These are the specs from the vendor:

1x Anti-static ESD High Temperature Resistance Mat 60cm x 100cm + Ground Wire + ESD Wrist
Description:
    100% brand new
    Type :Anti-static Mat
    60cm x 100cm
    Thickness: 2mm
    Weight: 1850grams / 1.85kg
    Temp resistance: 380c   

The Anti-static Mat is acid resistant, alkali-resistant, anti chemical flux, wear resistant, easyclean.

It was about 35 USD with free shipping. The top green layer is very elastic, so even with needle sharp probes it is almost impossible to pinch. The bottom layer is slightly conductive, black, and feels like rubber. The mat is heavy and flexible, it lays flat on the bench under it's own weight. It can stand a 350*C blob of solder for a few seconds without any damage. Mine came with a small fabrication defect, but this is another story.

The problem is THE SMELL. It has a very, very strong smell, like new car tires smell, but way, way more smelly.

I put the mat on the workbench, arrange all the tools, then after a couple of hours I undo the whole bench, and took out the mat because I couldn't stand the smell any more. All the time the doors and the windows were open.

I let it outside over night, but in the morning the smell was the same. Then I hang it in the direct sunlight, with a big fan to blow over it. For now, it has spent one full night outside, then 6 more hours outside in the sun with forced ventilation. It still smells as strong as yesterday.

- Could anybody that own an expensive branded mat please tell me if the expensive ones smells the same?
- Did anybody else have the same problem with anti-static mats?
- Is there any other way to get rid of the smell?
- How long will this smell last?
 

[RoGeorge]

After one full day in the sun, with a big fan continuously blow air on the ESD mat, the smell is the same.

In the meantime, I found that this post is somehow a duplicate of the https://www.eevblog.com/forum/chat/esd-mat-smell/
Sorry for that, I did search, but I used "anti-static smell" instead of "ESD smell". Seems like the blog search is verbatim.

Also found a possible recipe that removes the rubber smell: https://www.esedirect.co.uk/articles/post/how-to-remove-the-smell-of-rubber-matting.aspx
I already put the rubber mat in a bath tub half full with hot water, 150 ml dish washer detergent and 400 ml of white vinegar. During the last two hours, I scrub it a few times with a plastic brush, then rinsed with clean water and put outside to dry over night.

Will hope for the best for tomorrow.
 

[montreuilg@sympatico.ca]

I bought a similar mat two weeks ago and the VOCs are almost gone now.    ?

[sleemanj]

The smell goes away after a while in the open air (or maybe I just got used to it ;-)).

I have the same type of mats, sourced from Ali, for a couple years.

[Gary350z]

I already put the rubber mat in a bath tub half full with hot water, 150 ml dish washer detergent and 400 ml of white vinegar. During the last two hours, I scrub it a few times with a plastic brush, then rinsed with clean water and put outside to dry over night.

Be careful:

I have read on websites of companies that sell and/or make ESD mats that cleaning them with anything other than water or their approved cleaner can remove the ESD coatings on the mats, thus reducing there effectiveness. They say dish washer detergent is definantly too strong of a cleaner.

[b_force]

It's mostly the paint that smells so bad.
Not much you can do about it, except just putting it out in the open for a while.

I had it with many things like laptop cases, steering wheel sleeves and many other things

[eKretz]

Mine had quite the scent of rubber when brand new also, it fades over time.

[RoGeorge]

It worked!

The smell has gone a couple of hours later, after washing it with vinegar and dish soap:

cleaning them with anything other than water or their approved cleaner can remove the ESD coatings on the mats

For now I don't have a static fieldmeter, maybe will do some tests later.

Thank you all for your answers.

[rdl]

It worked!
...
For now I don't have a static fieldmeter, maybe will do some tests later.

Thank you all for your answers.

I wouldn't worry too much. I doubt the static dissipation comes from any kind of paint or surface coating that would wear away. Of course, the manufacturers and sellers certainly won't mind if you buy some of their expensive water with 2% soap added "approved cleaner".

[Gary350z]

I wouldn't worry too much. I doubt the static dissipation comes from any kind of paint or surface coating that would wear away. Of course, the manufacturers and sellers certainly won't mind if you buy some of their expensive water with 2% soap added "approved cleaner".

I don't know what coatings the mats may or may not have, but the manufacturers and sellers do say only clean with water, or their cleaner. So I don't think they are trying too hard to sell their cleaner. Who knows.

[rdl]

I doubt ESD mats have any coating at all. It wouldn't make much sense because eventually it would wear away. Most likely the properties come from specific additions made during the compounding process. It would be a good bet that the black, bottom layer is carbon loaded. If anyone has actual knowledge about these mats are really made, it would sure be interesting to know.

[RoGeorge]

Indeed, the bottom layer is made out of conductive rubber.

[Gary350z]

I doubt ESD mats have any coating at all. It wouldn't make much sense because eventually it would wear away.

I did some investigating on ESD mat cleaning.

I did not find anything about coatings on the mats.

The problem seems to be if you use the wrong kind of cleaner it may leave an insulative residue on the mat that prevents the mat from working properly. Cleaners with silicone in them are a problem.

See the attachment.

[rdl]

...
The problem seems to be if you use the wrong kind of cleaner it may leave an insulative residue on the mat that prevents the mat from working properly. Cleaners with silicone in them are a problem.

As someone who spent many years formulating oem industrial coatings, I'm familiar with both organic solvents and silicones and I have no problem believing that. Probably most things you would consider safe to wash your hands or your dishes with are okay for ESD mats also. Caution may be needed with skin cleaners though, because some could contain silicone compounds or other oils that might leave a residue. Personally, I've always used a weak solution of plain dish soap in water, but I also apply a final rinse/wipe with deionized or distilled water.

[thm_w]

ESD mat cleaner, 15-25% isopropanol: http://www.alliedelec.com/m/d/77822f9564d5c19e193262fadfa4273a.pdf
Elektramat, 7-9% dipropylene glycol monomethyl ether: http://www.ultrastatinc.com/ElectraMat%20SDS.pdf
Mat and table cleaner, 98% water, acid, some alcohols: http://www.americancleanstat.com/msds/6001ACL.pdf