SP Prefilled Formalin Containers - Available with or without pressure-sensitive inner seal. Our clarified, polypropylene wide-mouth containers are flexible, crack-resistant and autoclavable and allow visualization of specimens. Select sizes are available with a pressure-sensitive inner seal that protects against leakage and reduces exposure to formalin vapors. Lid is ribbed for easy handling, and the clear label lets you view the specimen. Containers are filled with 10% buffered formalin. Product is labeled with biohazard symbol to meet current OSHA standards for formalin.