Missouri regulators are warning nail and beauty salons against using razor blades to remove calluses during pedicures and other skin treatments.
The state Board of Cosmetology and Barber Examiners says it's received nine complaints about the use of a device called a "credo blade" to remove calluses and dead skin.
Missouri outlawed credo blades last year. The short-handled devices are similar to household razors. Officials say the blades can cause bleeding and infections and remove healthy skin.
State officials say calluses should only be removed by using a pumice stone or file.