Most chemical vapor deposited (CVD) diamond films contain impurities which increase their optical absorption in the regions of desired transparency. This paper examines the incorporation of these impurities, intentional or otherwise, and their effect on the IR absorption of CVD diamond, particularly in the 8-12 and 3-5 mu m regions. Oxygen, nitrogen, and hydrogen related absorptions have been observed in both regions. Evidence suggests that many of these impurities are located at the grain boundaries in diamond and their functional form is discussed. In this work, we clarify the origin of the absorption observed at similar to 2820 cm(-1), which was first observed by the authors and has since been observed in CVD diamond in other laboratories as well. The identification of these impurities in CVD diamond films has important ramifications for process conditions, particularly in systems where oxygen is used for growth enhancement.