If you do a web search for "vegan condoms" (yes, vegans use exotic and conscious search engines..) you will find that cruelty-free prophylactics are an item that is being sold. However, how could a common condom be not vegan? Is there any ingredient that comes from animals? Or any ingredient that is tested on animals?
Yes. Not all condoms are Vegan. There are different types of condoms available. While most condoms are made from rubber latex, condoms made from lamb cecums are also available. These are called lamb-skin condoms or just skin condoms in short.
Quoting from this article.
The term condom is actually a corruption of the name of an 18th-century British physician, Dr. John Conton, who provided condoms to France's King Charles II. The legendary lover Giovanni Casanova (1725-1798) used pieces of sheep intestine to protect himself against venereal disease.
- The first condom manufacturer in the U.S. was Schmid Laboratories. In 1883, Julius Schmid, a former sausage skin-maker, acquired a business that manufactured bottle seals from animal membranes. Five years later, Schmid used his experience with sausage casings and capping skins to manufacture prophylactic sheaths from lamb cecum.
The manufacturing process remains relatively unchanged since Schmid first manufactured condoms : the cecums are washed, defatted, and salted. The raw skins are then shipped to the finishing plants. New Zealand, which raises large numbers of sheep, is the primary source and initial processing center for most "skin" condoms.
The testing of these does not involve any animal products or animal cruelty..
After a curing period of several days, the condoms are sampled by batch and tested for leaks and strength. The first such test is the inflation test, in which the condom is filled with air until it bursts. Condoms are required to stretch beyond 1.5 cubic feet, about the size of a watermelon, before bursting. This test is considered most important because the elasticity of the condom keeps it from tearing during inter-course.
In the water-leakage test, the condom is filled with 10 ounces (300 ml) of water and inspected for pin-sized holes by rolling it along blotter paper.
- Condoms are also tested electronically. This involves mounting each condom on a charged stainless steel mandrel. The mandrel is passed over by a soft, conductive brush. If pin holes are present, a circuit will be established with the mandrel, and the machine will automatically reject the condom.
It is clear that the raw materials used in manufacture involves animal products, it is non-vegan.
To differentiate between skin condoms and latex condoms, there is a sign. Latex condoms have a green dot on the package. On skin condoms, it is replaced by a brown dot (at least in India).
Now. What's the problem with Latex condoms?
Most condoms are made from latex. In order to make latex smooth, most manufacturers use casein – a milk derivative — in the latex manufacturing process. Not only is this an issue for vegans, but a problem for the millions of people with casein or milk allergies.
See this article for details.
So most of the latex condoms are also non vegan due to the usage of casein, a milk protein.
SS' answer is covering almost all the aspects of the question.
Many condoms are indeed not vegan. As already mentioned, this is caused by casein usage in the manufacturing process. More information is provided by this article that deals with more technical details of how condoms are made:
Many condoms companies manufacture their latex condoms using casein—a milk protein. Some condoms may also contain milk powder. If you are a vegetarian, it may be important to you to only use vegan-approved products.
The same articles mentions a rather long list of manufacturers that their production process is free of animal products:
the following condom manufacturers have confirmed to the Vegan Society that their condoms are free from animal ingredients -- some, but not all, of the following condoms are also registered with the Vegan Society, the American Vegan Association, and/or Vegan Action: L. Condoms, Glyde Condoms, Sir Richard’s Condoms, RFSU Condoms (Birds 'N Bees, The Profil, Mamba, Thin and Grande), Condomi Condoms, Fusion Condoms, Durex Avanti Ultima Condoms, and Pasante Condoms.
Also, further digging might go into the manufacturing of various components used in the production process. I could find little information about this. The following is about the glycerin (source):
Glycerine can be animal- or plant-derived. It is also possible to produce glycerine from petrochemicals.
If plant-derived, glycerine is probably from soybeans. Animal tallow is a common animal source. I have received statements from several major manufacturers of glycerine. My general impression at this point (early 2010) is that it is typically derived from plant materials when used in food but one cannot always be sure, especially in cosmetics and bath and body products. It is best to ask the product’s manufacturer when in doubt.
Side note for other vegan issue - Testing on animals
This article explains how condoms are tested using physical models, not human (or animal ones) due to:
Condoms need to be tested to ensure that they meet certain standards. It is obvious that the truest model of condom performance is sex itself that humans are the most accurate models. It is otherwise difficult to know how much sensation is being lost, or what the real transmission rate of disease is.
[..] why condom testing is done with non-human (non-animal) physical models.
So, vegans are on the safe side when it comes to testing.