We have a ready-mix concrete plant and are trained with proper concrete etiquette. My concern is that concrete "craft" ideas are being posted online DIY sites without any warning of the possible danger from skin contact, especially for children.
When cement is dry, it contains calcium oxide, which is not particularly dangerous. However, when water is added to the cement, calcium hydroxide is formed, which is extremely alkaline with a pH of 12 to 13. The normal human skin has a pH of 5.5; therefore, wetted cement, concrete, can produce alkaline skin burns which progress and get worse without more exposure. A person may have wet concrete on his or her skin for hours without feeling any discomfort; however, the concrete is damaging the skin microscopically. Early identification of changes to the skin is important so steps can be taken to treat the affected area.
Concrete burns frequently produce discoloration of the skin, gradually changing to a deep purple-blue color, eventually progressing to painful burns. Some patients report red, inflamed skin near the affected area followed by severe blistering.
When creating a concrete project yourself, always wear goggles, gloves, long sleeves, pants, and full shoes or boots. When working with concrete, it is best to not allow young children into the area. Their skin is very sensitive, and they can quickly get splattered because of their mobility. When you are doing a project using concrete with children, be sure the environment is controlled closely and that the children are protected with goggles, gloves, long sleeves, pants, and full shoes or boots.
Concrete is an amazing combination of cement, rock/gravel, sand, and water. It is strong, and it lasts. It can be used for purposeful things as well as creative items. It is a beautiful medium. Just know the proper concrete safety etiquette.
There are hobby products that end in 'crete, ' and I am unfamiliar with what is in the product or if it is safe. Please, check your container for application instructions.
Fresh Find: Fun, inspirational 'crete' stones.