[Indoor air guide value for propan-1,2-diol (propylene glycol) : Communication from the Committee on Indoor Guide Values].

The Committee on Indoor Guide Values is issuing indoor air guide values to protect public health. At present, no suitable human studies are available for health evaluation of propan-1,2-diol in indoor air. In a well-documented subchronic inhalation animal study with rats, assessed as reliable, nasal hemorrhages were observed. This study leads to a LOAEC of 28.6 mg/m3 propan-1,2-diol for continuous exposure for the endpoint nasal hemorrhages. By applying a conversion factor of 2 from subchronic to chronic exposure, an interspecies factor of 2.5, and a factor of 10 for interindividual variability a health hazard guide value (RW II) of 0.6 mg/m3 propan-1,2-diol is obtained. A health precaution guide value (RW I) of 0.06 mg/m3 is recommended.