We investigated whether or not individuals who are allergic to formaldehyde and various formaldehyde-releasing preservatives must avoid exposure to another closely related formaldehyde-releasing allergen to which they were patch test negative. We found that in over 86% of cases a broad restriction of all formaldehyde-releasing preservatives was not required if the patch test was negative. Usually the patch test is predictive of which materials need to be totally avoided. Restriction of exposure to all of the formaldehyde-releasing preservatives may be overly restrictive.