USING FABRIC SOFTENERS
Static cling is annoying, but the products that counter it have some downsides
We like our clothes to feel soft and supple when they come out of the dryer and we would rather not find a sock hiding inside the sleeve of a sweater, aided and abetted by static cling. That’s why we reach for fabric softeners and dryer sheets. As is so often the case, when chemicals are introduced for convenience, there is an upside and a downside.
Historically, fabric softeners first appeared in the early 20th century, introduced because the dyes used back then left cotton fabrics with a harsh feel. These early formulations were made from corn, olive or tallow oil mixed with water. The idea was to leave a thin layer of fatty material on the fabric to smoothen the surface fibres and provide a softer feel. Because oil and water do not mix, soap was added as an emulsifier, preventing the oily and aqueous layers from separating.
As various synthetic fabrics came into use, another problem appeared, namely the horror of static cling. Every material in the world is composed of atoms featuring a positively charged nucleus, where most of the mass is concentrated, and negatively charged electrons that orbit the nucleus. A chemical bond is fashioned when adjacent atoms share electrons, resulting in the formation of molecules. Cotton, for example, is made of cellulose, while a synthetic fibre may be made of polyester or polyamide molecules. But electrons are rather loosely held, and when fabrics rub against each other they can be transferred from one piece to another. The fabric that has lost electrons will become positively charged, while the one that has gained electrons will now have a negative character. Unlike charges attract each other, and presto, we have static cling!
One way to counter the problem is to introduce moisture. Electrons travel readily through water, and the charges will be neutralized. This, however, defeats the purpose of a dryer.
Modern chemistry has come to the rescue with quaternary ammonium compounds, commonly referred to as “quats” with imidazoline methosulphate being a common example. Quats are a class of “cationic surfactants” that have a positive charge, allowing them to bind to negatively charged fibres. When added to laundry during the final rinse, quats will prevent static cling in the dryer. They will also provide the slip and lubricity that makes the fabric feel soft thanks to their molecular structure incorporating a chain of carbon atoms much like those found in fats.
Quats, however, can also make fabrics like towels and diapers less absorbent. This can be addressed by incorporating silicones into the formulation. These molecules can also coat fibres to prevent electron drift, and can contribute toward a soft feel without impairing the absorption properties of the fabric. Liquid fabric softeners also contain such emulsifiers as alcohol ethoxylates, since the conditioning ingredients are not typically soluble in water because of their oily nature.
Now for the downside. Quats can provoke allergic reactions and can also cause skin and respiratory problems. These, however, are seen mostly during occupational exposure, but it is possible, though unlikely, for someone to react to quats in fabric softeners.
Fragrances are another issue. These can contain numerous compounds that can provoke allergic reactions, as well as phthalates and synthetic musks that have endocrine disrupting properties. While it is essentially impossible to evaluate the risk, if any, posed by these, unscented products will work just as well.
Because of concerns raised about fabric softeners, “dryer balls” have appeared on the market. There are various versions of these, ranging from woollen ones to spiky polyvinyl chloride balls. According to the ads, “these incredible small round fabric softeners take the stiffness out of clothes, sheets and towels naturally, with no chemicals or toxins.”
Can these actually work? There may be a small physical effect. As the balls tumble with the clothes they may actually fluff up the surface fibres somewhat, leading to a softer feel. As far as chemistry goes, however, they fire blanks. Dryer balls do not release anything that can have an effect on static cling. I did give these balls a try without noticing any effect at all. That is in step with others who have reported carrying out more systematic experiments.
Finally, there is a more serious issue with fabric softeners. How well a combustible material burns depends on the extent of contact with oxygen. Cationic surfactants in fabric softeners coat surface fibres, separating them from each other and fluffing them up. This is especially the case when the surface is already fuzzy as with terry cloth, fleece or flannel. Cotton fabrics are fluffed up more than synthetics; the higher the polyester content of a material, the less flammable it is. Tests by Consumers Union in the United States have shown that using liquid fabric softeners in the rinse cycle can increase flammability as much as seven fold! Softener sheets that are put into the dryer do not have the same effect, presumably because they release fewer cationic surfactant molecules. Since liquid fabric softeners can build up on fabrics, repeated laundering can further increase flammability.
The risk of injury from burning clothing is of course tiny. Still, there are some 4,000 people every year in North America who require treatment for injuries suffered in this fashion.
The best advice is to avoid liquid fabric softeners when laundering terry cloth, fleece and flannel. Don’t use them on children’s clothing that have been treated with flame retardants, since fabric softeners reduce the protection. Dryer sheets are fine. Remember also that as little as 20-per-cent polyester content dramatically reduces flammability.
Polyester pyjamas for children are probably a safer option than cotton, but remember that going up in “a ball of flame” requires a source of ignition! You can lounge around in a comfy fabric-softened flannel robe to your heart’s content without worrying about it spontaneously bursting into flame. Just don’t do it next to a fireplace and don’t go dropping any cigarette ashes on it. And try not to get too hot under the collar when you read alarmist accounts suggesting there are nasty chemicals in fabric softeners that kill people.
‘Dryer balls’ have appeared on the market. Can these actually work?
joe.schwarcz@mcgill.ca Joe Schwarcz is director of McGill University’s Office for Science & Society (mcgill.ca/oss). He hosts The Dr. Joe Show on CJAD Radio 800 AM every Sunday from 3 to 4 p.m.