I just try to buy natural or the semi-synthetic cellulose fabrics, there's quite a variety.
Natural fabrics are cotton, silk, wool and linen of course, but the semi-synthetic fabrics like the rayons (viscose, modal, "bamboo", Tencel, Lyocell, Bemberg, and some sorts of artificial silk) are wood cellulose chemically rearranged so they're just cellulose when they reach you.
The fabric referred to as Acetate is cellulose acetate, so not pure cellulose like cotton and rayon but is just as biodegradable and contains no petroleum plastics.
Of course the production process for viscose rayons (not Tencel/Lyocell/Modal - those use a different process) isn't great. It uses carbon disulfide which is a neurotoxin. However it's not a persistent pollutant. Modern factories in the west try to capture and recycle as much carbon disulfide as possible (it's released from the rayon during processing and can be fed back in to the process) but as a lot of factories are in countries with poor controls on this it's hard to tell how many are doing this.
ive recently found some rayon shirts I really like, but how do you wash them without destroying them? everything I've read online says dry cleaning is the only way
For viscose most rayon a gentle cycle in a front loading washing machine is generally fine, though the more silk-like variants are less resilient. You might want to put it in a garment washing bag to make sure it doesn't get stretched while wet. If you don't have that it's dry-clean only.
Varieties like modal and Lyocell are machine washable.
Natural fabrics are cotton, silk, wool and linen of course, but the semi-synthetic fabrics like the rayons (viscose, modal, "bamboo", Tencel, Lyocell, Bemberg, and some sorts of artificial silk) are wood cellulose chemically rearranged so they're just cellulose when they reach you.
The fabric referred to as Acetate is cellulose acetate, so not pure cellulose like cotton and rayon but is just as biodegradable and contains no petroleum plastics.
Of course the production process for viscose rayons (not Tencel/Lyocell/Modal - those use a different process) isn't great. It uses carbon disulfide which is a neurotoxin. However it's not a persistent pollutant. Modern factories in the west try to capture and recycle as much carbon disulfide as possible (it's released from the rayon during processing and can be fed back in to the process) but as a lot of factories are in countries with poor controls on this it's hard to tell how many are doing this.