Earmuffs can be used in the workplace or recreationally for loud activities, e.g., concerts, shooting firearms, heavy machinery, mowing, etc. Hearing protection in the work place in the United States is regulated by organizations such as Occupational Safety and Health Administration (OSHA), Mine Safety and Health Administration (MSHA), and the National Institute for Occupational Safety and Health (NIOSH). Hearing protection can be included in hearing conservation programs if noise exceeds a certain criteria. OSHA recommends the use of hearing protection devices (HPD) when an employer is exposed to an average noise intensity of 85 dBA over an 8-hour shift. HPD is required when exposed to average noise intensity of 90 dBA or greater over an 8-hour shift. MSHA requirements are similar to OSHA. OSHA and MSHA require the use of hearing protection for workers who have not had a baseline hearing test or have had a shift in hearing thresholds, called a standard threshold shift.