Product details:

Wheaton Black Phenolic Screw Cap with Styrene-Butadiene Rubber (14B) lining material consists of homogeneous sulfur cured styrene-butadiene rubber. FDA Status complies with 21CFR 177.26, Rubber articles intended for repeated use. Excellent properties of resilience, resistant to moisture vapor. Satisfactory for most moderate chemicals. Not good for oils, strong acids and hydrocarbons. Autoclavable.