1. 21 CFR 170.3(i), Food additives, general provisions, definitions. https://www.ecfr.gov/cgi-bin/text-idx?SID=4c2a97f757ed27ea971578bb742f0f8b&mc=true&node=se21.3.170_13&rgn=div8. (Accessed 14 December 2017).
2. 21 CFR 170.39, Threshold of regulation for substances used in food-contact articles. https://www.ecfr.gov/cgi-bin/text-idx?SID=8ce6e5953c416682afc08514d1329da2&mc=true&node=se21.3.170_139&rgn=div8. (Accessed 27 June 2017).
3. 21 CFR 176.260, Pulp from reclaimed fiber. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfCFR/CFRSearch.cfm?fr=176.260. (Accessed 21 November 2017).
4. 21 USC 346, Tolerances for poisonous or deleterious substances in food; regulations. http://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title21-section346&num=0&edition=prelim. (Accessed 21 November 2017).
5. 21 USC 348, Food additives. http://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title21-section348&num=0&edition=prelim. (Accessed 21 November 2017).