A Sponge Is a Sponge Is a Sponge

The household sponge market is prime territory for staking out eco-friendly product claims. The yield is mostly fool’s gold.

Once upon a time, a sponge, in the sense of a physical object one used with soap and water, meant a natural sea sponge. All living sponges are part of one large category (phylum) of animals, but not all sponges are entirely soft and squeezable. The marketable sponge species comprise a select group whose members lack any hard skeleton. This surely offered a certain survival benefit at one time, but that benefit was sorely lacking once humans started diving for and over-harvesting these desirable species.

Even early on, what it was to be a sponge took on new dimensions, some deeply metaphorical. Thus, John Donne sermonized (1630), “Every man is but a spunge, and but a spunge filled with teares....” It was not until the mid- twentieth century, however, that the physical sponge took on new attributes, the synthetic supplanting the natural. Just after World War II, a group of former DuPont scientists came up with a process by which innumerable air pockets could be incorporated into viscose, the basic starting material of the synthetic textile rayon. At a basic level, the final product is made up of oxygen, cellulose, and then more oxygen. Et voilà: the O-Cel-O sponge was born. Left out of this promotional recipe, though, was another key industrial process ingredient – a toxic chemical called carbon disulfide. Just as with rayon and its sister viscose-based film end-product, cellophane, carbon disulfide is not retained in the final sponge. Consumers are safe, but in the factories making viscose, where poisonous carbon disulfide fumes can easily waft off into the workshop air, the workers can be as much of an endangered species as an over-hunted sea sponge.

Cellulose (and carbon disulfide)-based sponges continue to be a very big business worldwide. O-Cel-O is still a major brand. Outside the U.S., Spontex is huge, its adorable hedgehog mascot recognized worldwide. The cellulose sponge business has thrived for decades, long enough for the entry of “green cleaning” and the emergence of a myriad of internet sites promoting environmentally conscious shopping. At this point , after more than 50 years since its commercial introduction, to most consumers the good old-fashioned cellulose sponge is, well, good and old-fashioned. Cellulose from wood pulp (the trees stewarded responsibly, of course) is a paragon of renewable virtue. The knock-out eco-friendly double punch of sparing the sea sponge seals the green deal.

Ironically, other synthetic sponge wannabes have upped the ante for green chutzpah by virtue of being wholly based on synthetic polymers. One line of such synthetics is made of polyurethane, whose basic building block is any one of several asthma-causing chemicals known as isocyanates (https://www.psychologytoday.com/blog/household-hazards/200909/urethane-the-gift-keeps-giving). Beyond their main uses in insulation and foam packaging, the polyurethanes have any number of newer applications including in orthopedics (no asthma in patients just health care providers). The high-powered urethane sponge is just one more “innovation.” Even more important in the market is the ever-so-popular with consumers “eraser sponge” which comes under different brand names but all of which share the same melamine-formaldehyde based polymer platform.

These polymers, once they get to market, do not break down to yield their constituent chemicals and neither urethane or melamine-formaldehyde need be sold imbedded with additional agents (although imbedding synthetic sponges with antimicrobial chemicals such a triclosan is another matter; see: https://www.psychologytoday.com/blog/household-hazards/201408/the-buzz-antibacterial-soap-and-toothpaste) . The astute green aficionado will see where this is going. Or, as one web marketing site notes, “When the phrase ‘green cleaning’ comes up, it’s often in regards to the chemicals used to clean certain areas and surfaces. Going green also involves the tools you use. We previously wrote about re-usable items including dusters and flat mops that can be washed hundreds of times. There is also another tool you can use that requires no chemicals: melamine, like the [product name]. Green cleaning with melamine is one of the easiest ways to scrub your surfaces without chemicals.”

If you want to know who regulates sponges on the consumer side, you can always check out the Consumer Product Safety Commission’s straightforward Q&A - to whit – “Q: Would an animal-shaped bath sponge be considered a toy and require toy testing under ASTM F 963? A: Such products which are specifically marketed as and are clearly known as bath sponges are intended for cleansing purposes during a child’s bath. The small parts regulation, 16 CFR 1501, specifically exempts ‘grooming, feeding and hygiene products, such as diaper pins and clips, barrettes, toothbrushes, drinking glasses, dishes and eating utensils.’ Sponges could fall under this exemption. They’re not considered toys, but they are children’s products and would need to meet the applicable requirements for children’s products. The sponges therefore would not fall under the scope of ASTM F 963, but they would fall under the scope of the Federal Hazardous Substances Act, which includes torque and tension testing. (http://www.ul.com/global/documents/verificationservices/businesssegments/RS/CPSIA%202008%20FAQs%20112012.pdf). The FDA, on the other hand, has waded in on consumer concerns regarding cellulose-based tampons (http://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/PatientAlerts/ucm070003.htm).

In one way, we have come full circle. A new type of sponge, so far only for specialty applications, is taking us back to the oceans. Called “chitosan” sponges, these are made of a natural polymer built from sugar units, which is the backbone of cellulose as well. In this case, the polymer is derived from chitin, the basic material of the outer shells of shrimp, other crustaceans, and insects as well. Chitin is abundant on earth, but its processing is costly. Chitosan sponges may have an increasing role in innovative medical treatments (including as a delivery device for drugs soaked up and then slowly released), but don’t expect them any time soon on the supermarket aisle next to a miracle erasers and comfy cellulose sponges.

The viscose sponge is just a small part of the much larger story of rayon, cellophane and the occupational and environmental hazards of the chemical carbon disulfide. You can read more about that in my new book, Fake Silk (http://yalebooks.com/book/9780300204667/fake-silk).