In the case of identical number of hydrogen atoms substituted in the ring and concentrations, the toxicity clearly relied on substituted position on the ring with an order of ortho->meta->para-isomer.

• 在苯环上氢原子被取代的个数和浓度相同时毒性与氢原子被取代的位置有关，邻位最大，间位次之，对位最小。