Hi Klara, methylcellulose (MC) or hydroxypropylmethylcellulose (HPMC) are available non-toxic materials which are used e.g. in Food and Pharma Applications. Details about the various available grades are given in the document:
http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_096d/0901b8038096d9ff.pdf and for sample request please use the 2nd link. https://www.dow.com/en-us/contact-us-cig