Complex sentence: They are sometimes confused with fluorosurfactants, which have a significant bioaccumulation problem, however perfluoroalkanes do not bioaccumulate, and those used in medical procedures are rapidly excluded from the body, primarily via expiration.
Split into simpler sentences: They are sometimes confused with fluorosurfactants, which have a significant bioaccumulation problem. However perfluoroalkanes do not bioaccumulate, and those used in medical procedures are rapidly excluded from the body, primarily via expiration.