Cinder Block Raised Beds – Is there A Danger Of Chemicals Leaching Into The Soil?

Q: I have seen plans for making raised beds with cinder blocks. Is there any danger of chemicals leaching into the soil?

A: Once upon a time cinder blocks were made from cinders that were left after coal was burned at power plants. Cinders were used as the “aggregate” that is mixed with cement to make a cinderblock. Some cinderblocks are still made using fly ash from the power plant. But in any case the aggregate material is tightly surrounded by cement. It would be very difficult to dissolve the aggregate material to contaminate the soil of your raised bed.