SAR stands for Specific Absorption Rate. It is a measure of the rate at which energy is absorbed by the body when exposed to electromagnetic fields, typically from mobile phones and other wireless devices. SAR is measured in watts per kilogram (W/kg). Regulatory agencies such as the FCC (Federal Communications Commission) in the United States and ICNIRP (International Commission on Non-Ionizing Radiation Protection) establish SAR limits to ensure that exposure to electromagnetic fields does not exceed levels deemed safe for human health.