Sensitizing capacity of some trimers in p-tert-butylphenol-formaldehyde resin

Contact allergy to p-tert-butylphenol formaldehyde resin (PTBP-F-R) is not rare. This resin consists of a large number of substances, most of which are still unknown. For diagnostic and preventive reasons the chemical identity of the sensitizers should be known, as well as their sensitizing capacities, cross-reaction patterns and presence in the environment. The aims of this study were to investigate the sensitizing capacities and potential cross-reacting patterns for 4-tert-butyl- 2,6-bis-(5-tert-butyl-2-hydroxy-3-hydroxymethyl-benzyloxymethyl)-phenol (XIII), 4-tert-butyl-2- (5 - tert - butyl - 2 - hydroxy-benzyloxymethyl) - 6 - (5 - tert - butyl - 2 - hydroxy - 3 - hydroxymethyl-benzyloxy methyl)-phenol (XIVa) and 7,15,23-tri-tert-butyl-25,26,27-trihydroxy-2,3,10,11,18,19-hexahomo-3,11,19-trioxacalix(3)arene (XVIII) by the guinea pig maximization test. 4-tert-Butyl-2,6-bis-hydroxymethyl-phenol, 4-tert-butylbenzene-1,2-diol, 4-tert-butyl-2-hydroxymethyl-phenol, 4-tert-butyl-phenol, 4-tert-butyl-2-(5-tert-butyl-2-hydroxy-3-hydroxymethyl-benzyloxymethyl)-6-hydroxymethyl-phenol, 4-tert-butyl-2-[5-tert-butyl-3-(5-tert-butyl-2-hydroxy-3-hydroxymethyl-benzyloxymethyl) - 2 -hydroxy-benzyloxymethyl] - 6 - (5 - tert-butyl- 2 -hydroxy- 3 -hydroxymethyl-benzyloxymethyl)- phenol and were used as potential cross-reacting substances. In this study it is strongly indicated that the linear trimer XIII has a sensitizing capacity in the guinea pig which was significant when compared to the controls (p = 0.024). No cross-reactions were detected in animals induced with the linear trimer XIII. The linear trimer XIVa and the cyclic trimer XVIII failed to induce sensitization.