Soap shelf life
Does soap have a shelf life? Yes, but it is probably still effective.
While soap has an expiration date, it can still be effective if it foams and foams while washing.
Soap does expire, but if it still foams when you wash your hands, it should be effective.
Most store-bought soaps expire after two to three years.
Natural or handmade soaps can expire earlier, within a year, because the essential oils and fragrances can become rancid or moldy. The best way to keep soap is to keep it stored in cool, dark areas free of moisture.
Most soaps are regulated by the Food and Drug Administration (FDA), which requires all medications to have an expiration date. That is why you also see an expiry date on soaps.
While most manufactured brands last up to two years or more, some handmade soap makers recommend using their soap within a year of purchase. That's because the natural ingredients in some soaps can become rancid or moldy.
However, it is likely that your soap will still be effective even after the expiration date. You should know this.
Soap does expire but is probably still effective
Soaps are surfactants that reduce the surface tension of water and smooth the molecules, binding, trapping, and loosening soap and oil - and the germs they contain.
That is why bacteria and viruses physically slip from your hands when you wash with soap and water for 20 seconds.
Soap also helps kill germs because of its polar and non-polar ends in its molecular structure. The polar end helps dissolve the soap in water, and the non-polar end helps take the oil off your hands and pass it through the sink. It is the non-polar end that disrupts the outside of bacteria and viruses, causing them to crack and die.
Most manufactured soaps have an expiration date of two to three years. However, if soap still foams when you wash your hands, it can still be used effectively even after the expiration date. It doesn't matter if the soap is liquid or solid.
How to know when soap has expired
Soap can expire if it is cracked, dry and does not foam, or if it does not smell the smell it did when you first bought it.
Compared to manufactured products, soaps perfumed with essential oils and colored with natural plant ingredients may have a shorter shelf life due to the natural ingredients. These handmade, organic or natural soaps should still function as store-bought soaps but may expire sooner.
Essential oils are "volatile," meaning they tend to evaporate when exposed to air. Soaps can lose their fragrance when the essential oils that provide those fresh scents evaporate. For some naturally scented soaps, we recommend using them within three months of opening the box.
Another sign that soap is too old is orange stains. The orange color is because the oil in the soap becomes rancid. While the soap is still technically safe to use, it won't smell very good.
In general, as long as a bar of soap has not gone rancid, no mold has grown or it no longer foams properly, you should still be able to use it effectively after the expiration date.