Formaldehyde. Formalin; Methylene Oxide. CAS RN 50-00-0. Formula Weight: 30.03. Density: 1.09 kg/L. Stabilized (Methanol), Guaranteed Reagent, 36.5-38.0%. Meets ACS specifications. Stabilized with 10-15% methanol. Packaged in a fiber drum with plastic bag liner. 450mL.