The European baseline series: Criteria for allergen inclusion (with reference to formaldehyde releasers).

Existing criteria for inclusion in the European baseline series are summarized. Additional criteria are developed to aid decision making where the current criteria do not yield an unequivocal result. These include a consideration of whether an allergen (hapten) is better placed in a special series and the frequency with which an allergen cross-reacts with existing markers in the baseline series.