What can I use to cover my clone trays from light

I have my clones in a dome and tray, about 50 per tray. I do not have them in the black inserts, so they are just scattered along the tray. I was wondering if it is ok for me to use black trash bags to cover the rockwool from light by lining the clones up and taping the bags to the outside of the tray? Or will it cause the plants to absorb the chemicals from the black bags since they will be touching it? thanks!!

Trash bags have some funky stuff in them as far as chemicals go. Theyre not food safe and food should never be stored in them in large scale restaraunts. If theyre not actually touching them it should be fine though. Otherwise you wouldnt be able to work next to them, i just wouldnt go lickin em

they would eventually end up touching since I do not have my clones in the individual tray holder so they slide around in the tray whenever I move it around