As I mention each and every week, Marketplace is a 22 minute show and they did a 10-product countdown, giving them approximately 2 minutes per product, so they had to leave a lot of information out.
So, what does J-Cloth claim? Apart from being a re-usable, machine-washable, lint-free paper towel replacement, which they've established a long time ago, J-Cloth claims that its biodegradable offering is fully biodegradable, because it's made from biodegradable fibers. When called by Marketplace, they said that the fibers were cellulose from wood pulp. Unfortunately, their website doesn't seem to have any further details that I could find—and cellulose can mean a lot of things, from cotton to rayon to paper, all of which are biodegradable.
Marketplace says the biodegradable seal on the package is invented and doesn't represent any certification mark, and is there to "look official". When they asked the company, the company said that J-Cloths could go in a municipal green bin for compostable waste. The critic says J-Cloths are not certified compostable and so the city compost teams will pull it out and divert it to the landfill, and landfills are designed air tight and water tight and basically, nothing ever composts in them.
Well, cellulose is certainly biodegradable, as it's the main structural component of plants and plants biodegrade, so I don't see any reason why you couldn't put it in your backyard composter in the same quantities you put paper in it (also cellulose fibers). I have a worm composter instead of a bacterial one, and I put lots of paper in it. I think regular (non-worm) composters don't like as much paper as worm composters do, but can still take some.
You know, now I want to put a biodegradable J-Cloth in my worm composter and see if I can find it after the worms have done their thing—they simply don't eat what they can't eat, and I have to pick that stuff out when I collect the finished compost. That'll be an experiment of many months, however.
I guess that means the question is whether or not you can put the J-Cloth in a green bin for a municipal composting program. The answer to that seems to be "it depends". You'd have to look at what your city of residence has in the way of a composting program. A quick google survey has showed me that some places allow yard waste (grass clippings, leaves, branches, no food) only, but provide backyard composters for food waste, some allow kitchen scraps (food waste, no grass or leaves) only, some take nearly everything biodegradable, including vacuum bags, dryer lint, and used kitty litter, while others take nearly everything biodegradable but NOT yard waste, vacuum bags, or dryer lint. "Certified compostable", which the expert that Marketplace talks to, doesn't seem to mean much of anything either, in terms of what can go in the green bin; the cities I found listed acceptable items rather than referring to a certification.
My conclusion is that there's no evidence the J-Cloth isn't biodegradable as claimed, but before you put anything in your city's green bin, make sure you know what's allowed. There's a huge variability in what different cities accept, and assuming that because something is biodegradable your city will compost it is not a safe assumption—which has nothing to do with the J-Cloth, and everything to do with making bad assumptions.
Also, the manufacturer shouldn't have said it's green-binnable without asking what city the caller is in. That was sloppy and really puts them in a bad light, because it gives ammunition to people looking for false environmental claims—you can't just put a J-Cloth in many municipal composting programs, but that's because some of them are very specific in what they take.
10: Raid EarthBlends Multi-bug killer
9: Sunlight Green Clean Laundry Detergent
8: Obusforme EcoLogic Contoured pillow
7: Simple Green All-Purpose Cleaner
6: Eco Collection bath mitt
5: Vim PowerPro Naturals
4: Organic Melt ice remover
3: T-fal Natura frying pan
2: Biodegradable J Cloth
1: Dawn Antibacterial Hand Soap