The BTF study also found that prior to the air strikes, local technicians helped minimise the potential harmful effects of air strikes by "removing oil products that could be harmful to human health if spilt or burnt, such as transformer oil containing PCBs. Production was also accelerated to use up as much as possible of the crude oil, intermediate products and additives, and the final products were shipped to other locations. The remaining oil was mixed with gasoline, so that the tanks would ignite if hit, rather than leak into the soil and groundwater".