Ecowood Treated Pine Sleepers are made from plantation pine with safe Ecowood treatment to H4 level for in-ground use. Our Ecowood sleepers contain NO arsenic, chromium or amonia. They are approved Safe for kids playgrounds, kindergartens & schools, vegetable gardens & many other uses. Most treated pine sleepers are Garden Grade and not for structural walls, but a new F7 graded treated pine sleeper is now available.