The styrene block polymers identified in paragraph (a) of this section may be safely used as articles or as components of articles intended for use in contact with food, subject to provisions of this section.
Styrene block polymers | Molecular weight (minimum) | Solubility | Glass transition points | Maximum extractable fraction in distilled water at specified temperatures, times, and thicknesses | Maximum extractable fraction in 50 percent ethanol at specified temperatures, times, and thicknesses |
1. (i) Styrene block polymers with 1,3-butadiene; for use as articles or as components of articles that contact food of Types I, II, IV-B, VI, VII-B, and VIII identified in table 1 in § 176.170(c) of this chapter under conditions of use D, E, F, and G described in table 2 in § 176.170(c) of this chapter | 29,000 | Completely soluble in toluene | -98 °C (-144 °F) to -71 °C (-96 °F) and 86 °C (187 °F) to 122 °C (252 °F) | 0.0039 mg/cm2 (0.025 mg/in2) of surface at reflux temperature for 30 min on a 0.19 cm (0.075 in) thick sample | 0.002 mg/cm2 (0.01 mg/in2) of surface at 66 °C (150 °F) for 2 hr on a 0.19 cm (0.075 in) thick sample. |
(ii) Styrene block polymers with 1,3-butadiene; for use as components of pressure-sensitive adhesives that contact food of Types I, II, IV-B, VI, VII-B, and VIII identified in table 1 in § 176.170(c) of this chapter under conditions of use C, D, E, F and G described in table 2 in § 176.170(c) of this chapter, provided the pressure-sensitive adhesives be applied only to closure tapes for sealing containers having a capacity of not less than 160 cc (5.5 fluid ounces) and that the area of the adhesive exposed to food shall not exceed 4.03 cm2 (0.625 in2). The pressure-sensitive adhesive may contain terpene resins as identified in § 175.125(b)(2) of this chapter | 29,000 | ......do | ......do | ......do | Do. |
2. Styrene block polymers with 2-methyl-1,3-butadiene; for use as articles or as components of articles that contact food of Types I, II, IV-B, VI, VII-B, and VIII identified in table 1 in § 176.170(c) of this chapter | 29,000 | ......do | -65 °C (-85 °F) to -47 °C (-53 °F) and 86 °C (187 °F) to 122 °C (252 °F) | 0.002 mg/cm2 (0.01 mg/in2) of surface at reflux temperature for 2 hr on a 0.071 cm (0.028 in) thick sample. (Optionally, maximum net residue soluble in chloroform shall not exceed 0.00020 mg/cm2 (0.0013 mg/in2) of surface.) | 0.002 mg/cm2 (0.01 mg/in2) of surface at 66 °C (150 °F) for 2 hr on a 0.071 cm (0.028 in) thick sample. (Optionally, maximum net residue soluble in chloroform shall not exceed 0.00040 mg/cm2 (0.0025 mg/in2) of surface.) |
3. (i) Styrene block polymers with 1,3-butadiene, hydrogenated (CAS Reg. No. 66070-58-4): for use as articles or as components of articles that contact food of Types I, II, IV-B, VI, VII-B, and VIII identified in table 1 in § 176.170(c) of this chapter | 16,000 | ......do | -50 °C (-58 °F) to -30 °C (-22 °F) and 92 °C (198 °F) to 98 °C (208 °F) | 0.002 mg/cm2 (0.01 mg/in2) of surface at reflux temperature for 2 hr on a 0.071 cm (0.028 in) thick sample | 0.002 mg/cm2 (0.01 mg/in2) of surface at 66 °C (150 °F) for 2 hr on a 0.071 cm (0.028 in) thick sample. |
(ii) Styrene block polymers with 1,3-butadiene, hydrogenated (CAS Reg. No. 66070-58-4): for use at levels not to exceed 42.4 percent by weight as a component of closures with sealing gaskets that would contact food of Types III, IV-A, V, VII-A, VIII, and IX identified in table 1 in § 176.170(c) of this chapter, and in condition of use D as described under table 2 in § 176.170(c) of this chapter | 16,000 | ......do | ......do | ......do | Do. |
21 C.F.R. §177.1810