title: Vapor Pressure and Predicted Stability of American Contact Dermatitis Society Core Allergens.
abstract: BACKGROUND
  Accurate patch testing is reliant on proper preparation of patch test allergens. The stability of patch test allergens is dependent on several factors including vapor pressure (VP).
  
  
  OBJECTIVE
  This investigation reviews the VP of American Contact Dermatitis Society Core Allergens and compares stability predictions based on VP with those established through clinical testing.
  
  
  METHODS
  Standard references were accessed for determining VP in millimeters of mercury and associated temperature in degrees celsius. If multiple values were listed, VP at temperatures that most approximate indoor storage conditions (20°C and 25°C) were chosen. For mixes, the individual component with the highest VP was chosen as the overall VP, assuming that the most volatile substance would evaporate first. Antigens were grouped into low (≤0.001 mm Hg), moderate (<1 to >0.001 mm Hg), and high (≥1 mm Hg) volatility using arbitrary cutoff values.
  
  
  CONCLUSIONS
  This review is consistent with previously reported data on formaldehyde, acrylates, and fragrance material instability. Given lack of testing data, VP can be useful in predicting patch test compound stability. Measures such as air-tight multidose reagent containers, sealed single-application dispensers, preparation of patches immediately before application, and storage at lower temperatures may remedy some of these issues.
authors.affiliation: From the *Department of Dermatology, University of Minnesota; †Minneapolis Veterans Affairs Health Care System, Minneapolis, MN; and ‡Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV.
authors.forename: Paul C
authors.initials: PC
authors.lastname: Jou
authors.forename: Paul D
authors.initials: PD
authors.lastname: Siegel
authors.forename: Erin M
authors.initials: EM
authors.lastname: Warshaw
mesh_terms: D000485:Allergens / Q000737:chemistry*; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis*; D006801:Humans; D010328:Patch Tests / Q000379:methods*; D012955:Societies, Medical; D055548:Vapor Pressure
chemical_list: D000485:Allergens