Crimped polypropylene bristles for sweeping heavy debris Stiff bristles hold up on sidewalks, parking lots, and other rough surfaces; not affected by water or petroleum products Natural fiber Palmyra bristles for sweeping heavy debris Durable, tough, long-wearing; perfect for street crews, construction, and other demanding work sites Street sweeps are durable, tough, long-wearing; perfect for street crews, construction, and other demanding work sites BPA free Hardwood blocks