Polypropylene (PP-H) - high-quality general purpose engineering plastic material; the chemical name is polypropylene homopolymer, and it’s available in a range of grades and forms to suit many applications. PP-H has extremely good resistance to acids, alkalis and alcohol, salts in aqueous solutions and many solvents. Slight swelling may be caused by permanent contact with grease, oil and wax, but generally not enough to limit the use of the material. Aromatics and halogenated hydrocarbons will cause a reduction in useful working life. The material has no resistance to strong oxidising agents such as nitric or chromic acids, and halogens.