Found the Korean Delvac 1 ESP MSDS, it says 10-20% "1-DECENE, TETRAMER AND TRIMER HYDROGENATED". Isn't that PAO? Are there other, less hazardous types of PAO, which may not be disclosed in a Korean MSDS? D1 ESP - Korean MSDS The Korean M1 0w-30, for example, appears to have 70 - 80 % of this "1-DECENE, TETRAMER AND TRIMER HYDROGENATED". M1 0w-30 It makes me believe that there are no more than 20 % PAO in the mentioned HDEO, what do you think?