Fumes created during small scale frying are usually ventilated direct to atmosphere without treatment other than possibly a washable grease filter. On an industrial scale the fumes generated during large scale frying operations must be effectively captured and drawn away to protect the indoor environment and the fumes abated to protect the outdoor environment prior to final discharge. The length of ductwork prone to fatty deposition must be minimized and arranged so as to allow self-drainage of deposited oils. Downstream there must be fume treatment plant, usually a self-cleaning scrubber such as the RotoClone W. Often this will be sufficient but where the emission limits are especially stringent the scrubber may be followed by an odor abatement plant such as an Ultra-Violet reaction chamber, chemical scrubber or carbon based filter.