The role of isocyanates in fire toxicity

Fire Science Reviews

Table 3 Summary of exposure regulation and guideline levels for TDI, MDI and HDI. This table includes the lethal dose 50 (LC₅₀) for rats in ppm as well as the short term and long term levels for the respective airborne isocyanate from regulating organs

^aRat inhalation (4 h)
^bAs NCO-group
^cTen minute exposure
STEL Short-term exposure limit (15 min unless otherwise stated), AEGL1 Acute Exposure Guideline Level 1 “Notable discomfort, irritation, or certain asymptomatic non-sensory effects. However, the effects are not disabling and are transient and reversible upon cessation of exposure”, AEGL2 Acute Exposure Guideline Level 2 “Irreversible or other serious, long lasting adverse health effects or an impaired ability to escape”, AEGL3 Acute Exposure Guideline Level 3 “Life threatening health effects or death”, ERPG2 Emergency Response Planning Guidelines level 2 “is the maximum airborne concentration below which nearly all individuals could be exposed for up to 1 h without experiencing or developing irreversible or other serious health effects or symptoms which could impair an individual's ability to take protective action”, ERPG3 Emergency Response Planning Guidelines level 3 “the maximum airborne concentration below which nearly all individuals could be exposed for up to 1 h without experiencing or developing life-threatening health effects”, TWA Time weighted average (8 h per day during 40 h week unless otherwise stated), REL Recommended exposure limits
N/A indicates level not available/not applicable