CAS 79-41-4 appears in our catalog under these names: Methacrylic acid, 99+%, stab. with 250ppm 4-methoxyphenol , Methacrylic acid, 99%, stab. with 100-250ppm hydroquinone or. Offered by: Thermo Scientific (Alfa Aesar). Available pack sizes: 250g, 1kg, 3kg , 2000g, 500g.