why is formaldehyde used in vaccines
â¢ Formaldehydeâs use as an inactivating agent in vaccines is clearly. defined and well-regulated by the FDA.ii. â¢ Studies have shown that for a newborn of average weight of 6 - 8. pounds, the amount of formaldehyde in their body is 50-70 times. higher than the upper amount that they could receive from a single.