It was recently pointed out to me that what I do at home is not common practice and that it would be beneficial to share this knowledge to increase the environmental savings. So, I wash my household sponges in the dishwasher at the end of the day along with the days dishes.
Tips, tricks, life hacks... whatever you want to call them, they will reduce your environmental impact and save you money by keeping your household items working better for longer.
Synthetic sponges, pictured below, can be made of polyester, polyurethane, or vegetal cellulose. Polyurethane is used in polyester sponges for its abrasive qualities. Polyester sponges are more common for dish washing and are usually soft and coloured. Their manufacture relies on hydrocarbons which deplete the ozone layer plus they may give off formaldehyde. There is also an assortment of bleaches, sulphates and other chemicals. When incinerated the sponges may emit dioxins and other cancer provoking substances.
All good reasons to use fewer of them by making the ones you have last a lot longer. Plus washing them regulary means that they don't get smelly!
I also did some research for this article and found that these sponges can also be cleaned in the microwave if thoroughly wet. A 2006 study found that microwaving wet sponges for two minutes (at 1000 watt power) killed 99% of coliforms, E. coli, and MS2 phages, but Bacillus cereus spores required four minutes. NOTE that after some fires were caused by people trying to replicate the results at home with dry sponges, the study's author urged people to MAKE SURE THE SPONGES ARE WET.
Sponges can also be cleaned by soaking them in vinegar. Readers Digest suggest soaking overnight in a mixture of 1 cup of hot water, ½ cup white vinegar and 3 tablespoons salt, then rinse well in the morning.
I will continue to put mine in the dishwasher. I estimate that I only buy one packet of sponges each year, saving money and reducing my household's environmental footprint. Win, win.