Works well on synthetics, not cotton
TLDR: nice scent but this Arm and Hammer scent booster product is really only effective in scenting synthetic fabrics. It is basically a fragrance salt and there is nothing that will really help it bind to cotton. If you’re using it for synthetics you will be happy / if you’re hoping it will scent your cotton sheets and towels you will be disappointed. ———— Most of my laundry is cotton, and I could not detect any scent on it once it went through the dryer, however, this product *did give a nice scent to anything synthetic.* I realized it was my own fault for not looking at the ingredients, as I had not used scented products for a while. I had made a study of this issue previously due to someone in the household with sensitive skin. If you want scent to *last* on cotton, you’d likely need a product labeled with “encapsulated fragrance” or “with fabric softener technology.” Cotton is hydrophilic (loves water). It absorbs water easily, but at the same time, it doesn’t hold onto oily, hydrophobic fragrance molecules well. During the wash, the fragrances get rinsed away with the water instead of sticking to cotton fibers. Polyester, nylon, other synthetics (man-made fibers) are hydrophobic and have a plastic-like surface. Fragrance molecules are usually oily/hydrophobic, so they stick more strongly to these fibers, and scent lasts longer. This Arm and Hanmer product is mostly salt, baking soda, and fragrance oils, it relies only on the natural attraction of fragrance to synthetic fibers. Without capsules or cationic agents, cotton won’t hold much scent from this product. ————- Notes: The encapsulated fragrances would be something like “beads” products. Roughly speaking, little microcapsules attach and then break down during usage, releasing a little bit of scent. Some detergents have built in fragrance polymer systems that try to accomplish the same thing. Some warnings to not overuse beads as the product can clog drains in washing machine machines if they are not fully dissolving in your system, and can take time to degrade in water treatment plants, so some environmental considerations. The other common option, softener technology (liquid, or dryer sheets) usually has cationic surfactants or “quats” that bind to cotton’s negative surface. The downside of these is that they can make cotton less absorbent after a while, or make cottons feel a bit greasy or waxy. It doesn’t happen overnight, but could make towels less absorbent for example. If you go through cotton towels and sheets pretty regularly this might not be a concern for you, and you would rather have the scent. Older or cheaper encapsulation systems often used non-biodegradable polymers (like melamine-formaldehyde resins or polyurea). These break down into microplastics during washing and can end up in wastewater. Studies seem to indicate this makes up maybe 1% or less of the microplastics in water but for some people this might be a consideration while on their pursuit for laundry scent boosters. Newer systems: Some brands now use biodegradable encapsulation materials (starch, modified cellulose, alginate), but labeling is often vague. This is a whole other line of research that I leave to you. I have not yet found a perfect solution. I feel like beads provide potentially too much coating on my cottons and drains after a while, so I’ve decided to just use a high-quality detergent, and sachets in the linen closet. For a little special scent, this Arm and Hammer product is very nice for my delicate synthetic items. Read more