In the past, prior to the initiative to reduce or eliminate thimerosal from childhood vaccines, the maximum cumulative exposure to mercury via routine childhood vaccinations during the first six months of life was 187.5 micrograms. With the introduction of thimerosal-preservative-free formulations of DTaP, hepatitis B, and Hib, the maximum cumulative exposure from these vaccines decreased to less than three micrograms of mercury in the first 6 months of life. With the addition of influenza vaccine to the recommended vaccines, an infant could receive a thimerosal-containing influenza vaccine at 6 and 7 months of age. This would result in a maximum exposure or 28 micrograms via routine childhood vaccinations. This level is well below the EPA calculated exposure guideline for methylmercury of 65 micrograms for a child in the 5th percentile body weight during the first 6 months of life.