Your raised beds made from Macrocarpa planks will be safe except where sap wood is used (sometimes along edge). My husband cut down Mac's, we milled them and built our home from them. Beautiful wood too. More to the point we have dug up macrocarpa fence posts and they were not rotted after years of being planted! If you scrape an old post the macrocarpa smell is still there. The mist from milling the logs was so strong I felt a bit ill after a day of milling. Don't know what it is but bugs do not like it for sure.