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On page 11 of this ESD Book:

ESD sensitive device can experience a damaging discharge if touched by a person, even if that person is properly grounded. Increasing the electrical path's contact resistance is one way to control the speed of the discharge. A good way to accomplish this is by wearing static dissipative cots and gloves.

I thought antistatic gloves are not being used to avoid ESD, but to avoid fingerprints on electronics and whenever you want to wear gloves for that purpose, these gloves should be antistatic. Otherwise they can cause ESD.

Yes, ESD is a point-of-contact thing, but can antistatic gloves reduce ESD?

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You are right. If you wear gloves, they should be sufficiently conductive so that their surface does not retain a charge, which gets discharged through you to your connection to ground.

The purpose of all ESD precautions is to get everything at the same potential. It doesn't have to be 'ground', but that is the most convenient level to choose. So insulators have no part in this, they allow potential differences to exist. Conductivity is what's needed. If you need to use a glove, to protect components from skin oils and salts, then wear plain cotton. The cellulose fibre they are made from retains some level of moisture (there's no magic to being 'natural') which renders them slightly conductive, sufficiently so for ESD protection purposes.

Conductive gloves will not work for ESD protection by themselves. They need to be used as part of a full system that includes getting you, your worktop, your tools and all components at ground potential, and keeping them there. Wriststrap, conductive benchtop, both connected through safety resistors to a common ground are needed. Tools and conductive bags and tubes get grounded when placed on the bench or handled by you.

While it's true that adding extra resistance in series with you will reduce the level of current that flows from a charged you into a device, it's not the right way to do it. The right way is to avoid you being charged in the first place. Think of insulating gloves as seat belts / airbags, and not being charged in the first place as driving so you don't crash into things.

My heart sinks at work when a colleague approaches me, holding a circuit board that's intended for me, that's not in a conductive bag. Often they are gingerly holding it by some insulating part, apparently knowing there is an issue, but not knowing what to do about it. I make a point of touching them first to minimise the ESD problem they have caused, male or female, intern or CEO. Get at the same electrical potential, then pass the sensitive item. If it was insulated from them, then I find a large ground feature on the board, connector shells for instance, and take it by that, so that any current flows to a robust rather than sensitive part of the item.

This error happens because people do not understand the number 1 goal of ESD protection, everybody and everything stay at the same potential. People peddling insulation, or denying that charge accumulates on an insulated person, do not help.

Unfortunately, ESD unsafe practices are just that, unsafe, they do not guarantee failure. In fact, most people employing unsafe practices will get away with it all the time, and all people will get away with it some of the time. This means that failures are rare, and difficult to identify with specific times when they occurred. In industry, we need all the people to be working safely all of the time, which is why there are working practices which can at times seem a little draconian.

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    \$\begingroup\$ 'You' don't accumulate or retain a charge at all, that is pure mythology. 'You' are too wet and low resistance to retain or support a charge. Charge is accumulated on clothing/footwear, 'You' are just a resistive pointer to complete the circuit, that is why they earth you through a contact to station ground. Wearing antistatic cloves provides a consistent global R value for the skin (though it also helps prevent oils transfer from the skin). \$\endgroup\$ – Jack Creasey Jan 6 '17 at 17:34
  • \$\begingroup\$ You earth yourself through a contact to station ground to keep yourself at the same potential as station ground. You being at a different potential from station ground ===> you have accumulated a charge with respect to station ground. Duh! Try walking across a synthetic carpet in insulating shoes, then lick a filing cabinet. That belt you get is the charge you've accumulated jumping from your tongue to the filing cabinet. \$\endgroup\$ – Neil_UK Jan 6 '17 at 20:30
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    \$\begingroup\$ @JackCreasey Sounds like you need to take electronics 101. Pleas stop posting rubbish. It's difficult enough to get people to understand how to take ESD precautions, without you doing a Trump on them. If the carpet fibres get one charge, where does the opposite charge accumulate? \$\endgroup\$ – Neil_UK Jan 7 '17 at 7:16
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    \$\begingroup\$ @JackCreasey I've updated my answer with a bit more information, and background. Look up tribolectric charging for the walking on a carpet issue. Look up the many Q/As on this site for ESD protection, unfortunately some still contain a lot of rubbish. The central principle is keep everything at the same potential, everything, without exception, everything. If it achieves that consistently, then it's good. The difficulty is coming up with a system that poorly trained people can use consistently. \$\endgroup\$ – Neil_UK Jan 7 '17 at 9:08
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    \$\begingroup\$ @inf3rno. To allow charge build-up you don't need a good conductor. What you need is a very high resistance, which dry hair does have. I guess we should move static sensitive industries to areas that have nudist colonies ....that may help. \$\endgroup\$ – Jack Creasey Jul 14 '17 at 20:53
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They do provide an effective way of preventing ESD because they insulate the devices you're touching from your charged fingers. Since the ESD normally won't be strong enough to arc around or through the rubber, they're generally effective.

However, there are some downsides to them:

  1. They don't actually help dissipate your static charge, so if you bump a component with your forearm or other body part, you'll still get ESD.

  2. I've found them to make it difficult to manipulate small components and tools.

I would recommend a good ol' anti-static grounding strap instead. They don't interfere with your fingers, and they actually dissipate the static charge you build up, so if you bump a component with a different body part, ESD will still be effectively prevented.

Epilogue
I've done some more research based on the other answer and comments, and it appears I was probably using a really cheap set. It looks like they're more commonly made of nylon and other materials that actively help dissipate the charge rather than just act as a resistive barrier. I still stand by my recommendation though: it's still better to prevent yourself from becoming statically charged in the first place, and I find that working with bare fingertips is almost always easier.

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    \$\begingroup\$ The gloves aren't made of rubber, i think. Polyester fabric with conductive fibres. \$\endgroup\$ – Marty Jan 6 '17 at 17:28
  • \$\begingroup\$ I must have used some really cheap terrible ones then. They were definitely rubber, but I didn't have a part in selecting or purchasing them. \$\endgroup\$ – skrrgwasme Jan 6 '17 at 17:29
  • \$\begingroup\$ Maybe those were protective gloves and the polyester gloves are dissipative. \$\endgroup\$ – Marty Jan 6 '17 at 17:38
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    \$\begingroup\$ Normally they are Nitrile (which is a very special grade of rubber, so you'd never call it rubber) or Nylon/carbon. \$\endgroup\$ – Jack Creasey Jan 6 '17 at 17:39
  • \$\begingroup\$ @Marty There are different glove materials: superiorglove.com/pages/blog/anti-static-esd-gloves \$\endgroup\$ – inf3rno Jul 14 '17 at 2:27

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