title: Toluene diisocyanate concentration investigation among TDI-related factories in Taiwan and their relations to the type of industry.
abstract: OBJECTIVE
  To determine nationwide 2,4- and 2,6-toluene diisocyanates (TDI) concentrations among polyurethane (PU) resin, PU foam, and other TDI-related industries in Taiwan. The ratios of 2,4-/2,6-TDI and the noncarcinogenic risk among these three industries were also investigated.
  
  
  METHODS
  Personal and fixed-area monitoring of TDI concentrations as well as questionnaires were performed for 26 factories in Taiwan. The modified OHSA 42 method was applied in sampling and analysis. Noncarcinogenic hazard index was estimated for these three industries based on the average concentration measurements.
  
  
  RESULTS
  Significant differences of TDI concentrations were found among the three industry categories. For personal monitoring, PU foam was found to have the highest TDI levels [18.6 (+/-33.6) and 22.1 (+/-42.3) ppb for 2,4- and 2,6-TDI], Others average [8.3 (+/-18.9) and 10.2 (+/-17.2) ppb], and PU resin lowest [2.0 (+/-3.5) and 0.7 (+/-1.2) ppb]. The estimated average hazard indices were found to be 310-3310.
  
  
  CONCLUSIONS
  A substantial percentage of airborne TDI concentrations among in Taiwan industries exceeded current TDI occupational exposure limit, and significant difference of TDI levels were found among the three industry categories. The control remedy for the tasks of charging and foaming should be enforced with the highest priority. A separate 2,6-TDI exposure standard is warranted.
authors.affiliation: Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC.
authors.forename: Hui-Jung
authors.initials: HJ
authors.lastname: Yeh
authors.forename: Tung-Sheng
authors.initials: TS
authors.lastname: Shih
authors.forename: Perng-Jy
authors.initials: PJ
authors.lastname: Tsai
authors.forename: Ho-Yuan
authors.initials: HY
authors.lastname: Chang
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis*; D006801:Humans; D007221:Industry; D016273:Occupational Exposure / Q000032:analysis*; D011140:Polyurethanes / Q000032:analysis; D018570:Risk Assessment; D013624:Taiwan; D014051:Toluene 2,4-Diisocyanate / Q000032:analysis*
chemical_list: D000395:Air Pollutants, Occupational; D011140:Polyurethanes; D014051:Toluene 2,4-Diisocyanate