Abstract: By experiments of 25# Karamay transformer oil combustionin smoke box, the soot particles and PAHs emission factor(EF) were identified. The results indicated that, the EF values increases with the amount of burned oil and then decreases and remains steady with small fluctuation; The average value of EF for smoke from steady stage using large smog chamber was less than that using small chamber; The PAHs profiles from the combustion of new and wasted oil are the same, dominated by mid-to-high ring compounds, and are significantly different from those in transformer oil dominated by low ring compounds; The characteristics of the EFs for mid-to-high ring compounds varying with the amount of burned oil were more similar to those of smoke; The EF of the total PAHs for new oil combustion smoke from steady stage was higher than that for decommissioned oil, and the toxicity was dominated by benzo(a)pyrene.

Key words: transformer oil, combustion smoke, polycyclic aromatic hydrocarbons, emission factor