Air levels of volatile organic compounds following indoor application of an emulsifiable concentrate insecticide

Insecticidal formulations contain volatile inert ingredients that may be responsible for many of the general health complaints associated with indoor applications. Recent indoor air modeling results suggested that the levels of these volatile organic compounds (VOCs) could be high enough to cause health complaints among certain individuals. To confirm these findings, we performed broadcast and perimeter insecticide applications in four identical, unoccupied student apartments at Rutgers University. Passive dosimeters were used to obtain time-weighted average VOC measurements during the 24 h following each application. Levels were consistently higher in the apartments treated with broadcast applications, reflecting the greater amount of material applied by this method. Peak broadcast levels (21 mg/m³) were similar to peak levels generated by the model and were in the range expected to result in health complaints. Peak perimeter levels were approximately two- thirds as high as peak broadcast levels. Both broadcast and perimeter applications peaked around 10-14 h following application, which is considerably later than the model prediction (2-4 h). These results suggest that the potential for exposure may be greater than originally predicted and that ventilation and reentry recommendations may need to be prolonged well past the 3-6 h implied by the model results.