Does anyone know if card sleeves commonly contain Bisphenol A (BPA)? And if so, which brands do, and which are BPA free? I would prefer to use BPA-free sleeves if possible. I have not had any luck finding an answer to this question.
To answer the question, there are a lot of plastics that are suitable for use as card sleeves. None of them use Bisphenol-A as a plasticizer or monomer; that particular chemical is used primarily to make polycarbonates, which while optically clear are generally too stiff for use as flexible sheets or films (though they're great for applications requiring high impact resistance, like eye protection). So, you don't have to worry about Bisphenol A in your card protectors.
The two plastics you're most likely to see as clear films in your card protectors are poly-ethyl terephthalate (PET), and poly-vinyl chloride (PVC).
PET in fibrous form is known commercially as polyester, though in the chemical industry there are a lot of "poly-esters". This one is formed by bonding ethylene glycol into chains using a phthalate diester to glue them together. As a plastic, it's commonly used in disposable food storage containers, especially soda bottles. It's also commonly used for blister and clamshell product packaging. PET replaced cellulose acetate as a film stock for photos and movies, and also for transparent overlays, so it's definitely got the optical clarity to be used for card protectors.
The dangers of PET come when it's heated. It's perfectly stable at cold to tepid temperatures, making it just fine for packaging refrigerated foods, but when heated it can release the phthalate compounds into the food. Most of us get plenty of exposure to phthalates, and the vast majority do no real harm, but some combinations of alkyl-phthalates are endocrine disruptors which cause hormonal changes, and can cause birth defects and certain cancers.
Poly-vinyl chloride is one of the "wonder-plastics" that was used to do everything, until it fell off its pedestal. It still does a lot; it's seen in drainage and irrigation piping, upholstery, clothing, suction cups, self-adhesive window clings, clear flex tubing, clamshell and bubble packaging, and a host of other uses. It's generally prized for its toughness, even when it's plasticized beyond all recognition; a lot of other polymers lose too much of their tensile strength when too much plasticizer enters the picture.
Now the bad news. First off, the vinyl chloride monomer (VCM) turns out to be carcinogenic; it's fine as a polymer, but people making the stuff and people who come into prolonged contact with severely degraded PVC products can be at risk. Second, most usages of PVC require it to be more flexible than it is in its raw form, requiring the addition of a plasticizer. This is usually a phthalate, like in PET, but here it's a "mix-in"; the phthalate compound works itself into the polymer structure to "loosen" and "space out" the polymer chains, making them flexible. This means they're more readily released under the right conditions (brand-new vinyl products will even "off-gas" excess plasticizer for a few months after they're made and there's not much you can do about it). Some of the phthalates used in PVC cause even more problems than Bisphenol-A; there is evidence to show that a common plasticizer used in PVC piping, di-ethylhexyl phthalate (DEHP), causes feminizing characteristics in males, male obesity, and cardiac problems.
So I guess the moral of the story is, don't put your card protectors in the microwave along with your lunch.
There are a few safe alternatives if you can find them:
Polypropylene is a food-grade plastic used for a variety of applications from food storage containers to durable consumer goods. One form of it, biaxially-oriented polypropylene or BOPP, is made by extruding and then stretching a sheet of the plastic in perpendicular directions, aligning the polymer chains. When this is done, the material becomes crystal clear, and is used in this form for bags holding snack foods, shredded cheeses, candies, salad greens, etc. The material has no plasticisers and so is food-safe, as well as being dishwasher and microwave safe, making it good for food storage containers. BOPP would definitely be clear enough to hold your cards; in fact it's used for sleeves to hold comic books and trading cards. However, heat-bonded seals between layers of the stuff are more delicate than with other plastics (when re-heated it gets harder), and there's a tradeoff between overall durability and clarity; too thick and the plastic starts turning milky.
Polyethylene is the other major food-safe plastic. It comes in two basic types; low-density and high-density, both of which are generally microwave and dishwasher safe. HDPE is used for milk jugs, butter tubs, and a host of thin-walled flexible containers like for chocolate syrup; low-density is used in reusable squeeze bottles, and also in sheet-based products such as Ziploc bags, drop cloths, vapor barrier, etc. Much like polypropylene, polyethylene doesn't need a plasticizer, so it's safe for food prep and storage, and is another common plastic for food storage containers, especially the more disposable kind like Gladware. The downside it that it's never really crystal-clear; it always has that slightly milky, hazy look like looking through a freezer bag.
Plastic Containers Made with BPA Used in Food Preparation. Plastic containers have recycle codes on the bottom. Ingeneral,plastics that are marked with recycle codes 1, 2, 3, 4, 5, and 6 are very unlikely to contain BPA. Some, but not all, plastics that are marked with recycle code 7 may be made with BPA.
BPA is a chemical that has been around for years, and it would be quite difficult to avoid any contact with it anyway.
BPA stands for bisphenol A. BPA is an industrial chemical that has been used to make certain plastics and resins since the 1960s. In particular, BPA is found in polycarbonate plastics and epoxy resins.
Polycarbonate plastics are often used in containers that store food and beverages, such as water bottles, and baby bottles and cups. [...] toys and other consumer goods. [...] food cans, baby formula cans, bottle tops and water supply lines. [...] dental sealants and composites [...] and thermal paper products, such as cash register receipts [...]
The studies that claim BPA might pose a danger have methodological issues
The European Food Safety Authority (ERAS) - said that the amount considered safe to ingest on a daily basis for life should be raised by a factor of five.
Many of the studies that show adverse effects in rodents given small doses of bisphenol A subcutaneous injections. Most of the studies in rodents that did not show adverse effects even in high doses used the oral route.
there is "a 500,000 fold difference between the lowest oral exposures in animals associated with any adverse effects and the oral human exposure," [...] By any measure, this does not constitute a health risk. We get vastly more estrogenic chemicals from eating nuts, cereals and bread.