There are all sorts of buzz words used today to make you think that fabric is free from chemicals. Natural, organic and eco-fibers are the most common descriptions of material that leads one to believe that there are no petroleum-based products used in manufacturing. However, there is a test that you can perform to find out the truth behind how natural your fabric really is.
    The Burn Test: Snip off a small square piece of fabric and place on a fire resistant surface, such as a metal pan. Place in a sink to contain. Light one corner of the fabric with a match or lighter.
If it is a natural fabric, it will not shrink from the flame or begin to fuse. It will smell a bit like burning newspaper and the ash left behind will be grey and light.
If the fabric is synthetic, it will fuse and curl up. The smell is somewhat putrid, like burning hair or plastic. There are various smells that can occur because of the different chemicals used, but none are pleasant.
This type of fabric also usually puts the flame out, leaving behind a heavy, sooty black ash. Once the fabric has burned, douse with water and toss away.
The stronger the odor determines the amount of chemicals used. For instance, fire- retardant or water-proof fabrics have several chemicals mixed together to make fabric safer.
There are pros and cons to selecting natural over synthetic, but people with severe allergies find that natural works best.