Yes but there is a big difference between soft and hard. I'll take the hard and you can have the soft.
Most clear plastic products you will run into that claim any degree in inertness will be made of polyethyleneterephthalate (PET, trademarked as Mylar). Some might be polycarbonate, but mostly PET. PET has some flexibility even as 100%, but 100% polyvinylchloride (PVC) is a really hard/brittle plastic and has to be "plasticized" by the inclusion of materials that can leech out and get messy.
Let's say they are. But the hard holders don't have sharp edges that can scratch the coins when they are put into or removed from the flips. The hard holders hold the coin securely and allow no movement so no wear can be imparted to the coin like is done when a coin slides around inside a flip or 2x2. And hard holders are thick to protect the coins, unlike the thin covering of 2x2s that can allow a coin to be scratched right through the mylar. Point is, there's more to it than just the material they are made of.
Why would Doug disagree with the use of the Beilstein test? It is a well known and commonly used chemical analytical test for halogens.
I'm sure many will disagree with me, but I worry about paper dust with cardboard 2x2s, and the staples scare me.
Why ? Simple, because I believe the copper wire itself plays a part in this test. Use a steel wire, and you may well get different results.
But as long as the same protocol is used consistently and a standard is established, then there should be no issue at all.
I think he means those little 2x2 zip lock bags that some people put coins in. I don't use them but some sellers on ebay have sent me coins in them.
With your user name and you don't get it ? What color does copper turn when it corrodes ? Green. So do you think it's just a coincidence that the flame burns green ? You can put other things on a copper wire and it'll burn green too. That's why I have no confidence in the test.
The Intercept Shields and Quadrum Intercepts are the only way for me. They are secure, provide visual access and are guaranteed to prevent environmental damage for 15 years (although I don't know how they would pay off the guarantee).
What dust. The flip is sealed. The entire side which touches the coin is mylar with the dust removed and no possible way for duct to enter the area which protects the coin.
Let me barge in here and 'splain. The Beilstein test is to test for the presence of halogenated compounds although it is mainly used to test in chlorine is present. It is a very sensitive test and I don't know any non-halogen containing compounds that will give a positive test. Do you? What are they. I even ran it recently to see if it would work with a butane lighter. I stripped a plastic coated electric wire, stuck it in a butane flame to clean off any residue and heat it up to a temperature such that it would react with any chlorine in the flip I tested, giving some copper chloride which gives the green flame. I touched the hot wire to the flip and melted some material on it. I then returned the wire to the flame and saw the green color. I burned off all the residue, reheated the wire and touched a polyester flip and then burned the residue stuck to the wire in the flame...no green color. Sorry, I have used this test in the lab many times and don't know of any false positives.
Urea, thiourea, pyridine, and certain other nitrogen compounds and acids can produce a false positive on the Beilstein Test. What I meant by "false positive" in my initial response was that assuming Doug's point was with merit (which I disagree with him), his argument would cause him to conclude that it is oversensitive and would give false positives. A negative result would be useful adopting his logic. I wouldn't expect to find any of the compounds above in coin flips anyway (unless you spilled coin dip on them), and if all contaminants properly removed, would suggest the presence of a non-fluorine halogen.
Even if you assume that you get all the dust off the inner side of the mylar, which you usually can't, dust can and does still migrate through from the outer edges of the mylar, over time, between the mylar and the cardboard to get on the coin. 2x2s are an easy and inexpensive way to store coins, but they have several downsides, cardboard dust is just 1 of them. And while you can try to avoid the dust problem, and try to avoid the other problems as well, it is better to just avoid 2x2s. Assuming you want to protect your coins as best you can.
I'm not a chemist and don't pretend to be, you know that. So I would even try to argue the chemistry. But I don't need to be a chemist to see with my own eyes that burning things on a copper wire can produce green or greenish flame. My only point, my only objection, is with the copper. My suggestion if you will - is to not use a copper wire to conduct the test. But instead use something else, like steel. Even a common stainless steel kitchen fork will do to conduct the test. And it is far more likely for anyone wanting to conduct the test to have a fork than it is for them have a piece of copper wire. That's all.
However I respect your opinion and "There are more things in coins than can be explained by simple-minded chemistry". One of the things about the test is the necessity of the copper wire. At a high temperature, the copper or copper oxide reacts with the plastic to form copper chlorides. Stainless steel won't form these compounds. There can be false positives with some nitrogen containing materials which are not common in plastics. I was concerned that not all households might have a butane lighter, but it is hard for me to conceive of a household that can't come up with a piece of copper wire. BTW, try some "stuff" on a copper wire and see if you get green. I don't think you will.
And that's the reason I question the validity of the test - because I believe it is the copper making the flame green - not the plastic. I have, which is why I said what I did. And also why I question the test. Next you're going to want me to define "stuff". Well I'm talking about other plastic flips, other plastics (none of which had the softening agents in them), even some different paper products, basically anything that I could get my hands on that would burn. And when burned on copper some of it would have a greenish flame, on steel it would not. I used to test all sorts of things regarding coins and the hobby, and make note of my own observations. And when my observations would differ from what it said in some book or internet article, then I would wonder why. And I learned long ago, at a very young age, that you can't always trust "science". edit - I suppose the most important point is that this burning test is not even necessary to determine whether flips are safe to use for coins or not. There are other ways, simpler ways, to find out. The smell for instance, the smell of PVC flips is quite distinctive. If the flips smell like a new shower curtain - you don't want to use them. If the flips feel even remotely stiff when you flex them, you don't want to use them. If they crack when bend them repeatedly, you don't want to use them. And all of these things are reliable, and require no burning of plastics. So, if there is a question on the validity of the burning test, and based on my observations there is, don't use it. And instead use one of the other very simple and easy ways.
