In May 2000 the National Highway Traffic Safety Administration (NHTSA) issued the final rule for the Advanced Air Bag regulations effective MY 2004 for vehicles to be sold in the United States. These regulations are in response to the air bag-induced injuries seen in the field, especially to children and short women. Advanced air bags require a vehicle manufacturer to design air bags for a broad array of occupants: 12-month-old, 3-year-old and 6-year-old children, and 5th percentile adult females, as well as 50th percentile adult males with new and more stringent injury criteria. Requirements for minimizing air bag risks include automatically turning off the air bag in the presence of young children or deploying the air bag in a manner much less likely to cause serious or fatal injury to out-of-position occupants. Technologies that disable the air bag in the presence of young children or adults in out-of-position are termed as "suppression technologies.' To test the ability of those means to detect the presence of children, the rule specifies that child dummies be placed in child seats that are, in turn, placed on the passenger seat. It also specifies various tests that have to be conducted with unrestrained child dummies sitting, kneeling, standing, or lying on the passenger seat. This paper discusses air bag suppression technologies under consideration to meet these new regulations. It gives a brief introduction to the child seat detection schemes, compares the weight-based technologies and points out the key elements of proximity sensing.