Perilla oil was a critical component in creating durable earthen floors. In Japan, perilla oil was important for fueling oil lamps until early 16th century, before it was overtaken by rapeseed oil. The oilseed contains drying oil elements and was imported in bulk as a substitute for linseed oil into the United States from Japan, until the supply was interrupted by war. In Korea, perilla oil pressed from the untoasted seeds were used to fuel lamps and to oil floor papers. The press cake remaining after pressing perilla oil can be used as natural fertilizer or animal feed. Perilla oil Perilla oil
Oil platform onshore. Subsea facilities are also easier to expand, with new separators or different modules for different oil types, and are not limited by the fixed floor space of an above-water installation. Offshore oil production involves environmental risks, most notably oil spills from oil tankers or pipelines transporting oil from the platform to onshore facilities, and from leaks and accidents on the platform. Produced water is also generated, which is water brought to the surface along with the oil and gas; it is usually highly saline and may include dissolved or unseparated hydrocarbons. The world's deepest oil platform is the floating