What Is Cotton / Denim Insulation?

"Method and form: It comes in batt form like fibreglass and stone wool. It performs better than fiberglass during high winds and at low temperatures; it is extremely effective for sound absorption and thermal performance; easier installation than fibreglass; no protective gear needed; it contains 10% boron-based fire retardant (a natural non-toxic mineral),and it's resistant to fungus, mold, and pests."
https://www.ecohome.net/guides/2372/choosing-the-right-insulation-the-pros-cons-and-applications/

"Because cotton is a natural and renewable resource, it is one of the most eco-friendly insulation options on the market. Leftover blue jean scraps are shredded and recycled into thick batts that fit into your walls just like fiberglass. To make it safe for humans as well as the environment, companies treat the cotton with a borate solution, so the insulation isn’t flammable.

Cotton is also a natural insect repellent, doesn’t contain formaldehyde and doesn’t cause respiratory problems. However, compared to fiberglass, it is incredibly expensive, costing nearly twice as much."
https://inhabitat.com/7-eco-friendly-insulation-alternatives-for-a-green-home/

"Cotton insulation is a green building material that requires less energy to produce and is far more renewable than its largest competitor: fiberglass. Even those homeowners without environmental concerns are often won over by this product that has better acoustical properties and is easier to work with than its competitors."
https://homebuilding.thefuntimesguide.com/recycled_cotton_insulation/

"Cotton insulation was manufactured from the late 1930s through the early 1950s. It's made a comeback in the last few years and is touted as a green building product. Some is made from raw cotton while other is recycled cloth or scraps from denim manufacturing."
https://www.inspectorsjournal.com/topic/7714-loose-fill-cotton-insulation/

"Since cotton insulation contains up to 85% recycled cotton product, it's the ideal sustainable building material. If you are working to certify your green home, cotton insulation will help you attain that goal. For example, recycled cotton insulation earns points in 8 different LEED categories and prerequisites:"
http://www.green-home-source.com/cotton-insulation.html

"Cotton insulation is made of recycled cotton clothing, like blue jeans, and requires less energy to produce than fiberglass and polyurethane foam. Completely natural, the material does not vent toxic chemicals like formaldehyde and has better sound dampening qualities than chemically formulated materials. Cotton is safe to use and does not require protective gear during installation like its closest competitor, fiberglass. A 3 1/2-inch-thick "bat" of cotton provides insulation rated R-13 for a standard wall. Also unlike fiberglass or polyurethane foam, it can be reused."
https://oureverydaylife.com/how-does-cotton-help-insulate-12150246.html

"Denim insulation is an eco-friendly non-carcinogenic recycled material. It has a multi-dimensional microstructure that isolates and traps sound waves to control noise. With an STC of 52 and an NRC of 1.15, it can provide superior sound suppression in Renos or new builds."
https://bettersoundproofing.com/is-denim-insulation-good-for-soundproofing/