The following substances may be safely used as adjuvants in the manufacture of foamed plastics intended for use in contact with food, subject to any prescribed limitations:
| List of substances | Limitations |
| Azodicarbonamide | For use as a blowing agent in pol-yethylene complying with item 2.1 in § 177.1520(c) of this chapter at a level not to exceed 5 percent by weight of finished foamed polyethylene. |
| 1,1-Difluoroethane (CAS Reg. No. 75-37-6) | For use as a blowing agent in polystyrene. |
| Isopentane | For use as a blowing agent in polystyrene. |
| n-Pentane | Do. |
| 1,1,2,2-Tetra-chloroethylene | For use only as a blowing agent adjuvant in polystyrene at a level not to exceed 0.3 percent by weight of finished foamed polystyrene intended for use in contact with food only of the types identified in § 176.170(c) of this chapter, table 1, under Categories I, II, VI, and VIII. |
| Toluene | For use only as a blowing agent adjuvant in polystyrene at a level not to exceed 0.35 percent by weight of finished foamed polystyrene. |
