Q: What Businesses require a Grease Trap? A: Mainly Cafe's, Restaurants, Bakeries, Takeaways, Butcher's shops and various other food preparation businesses. The purpose of a Grease Arrestor/Trap is to keep the fats and oils out of the Authorities sewer lines and they also serve as a means of preventing blocked drains on your property. The main reason for complying with the Regulations is that your business will not be able to open unless the list of requirements regarding Grease Trap installations are met. Most Council Authorities and the Health Department regulate that they are installed and inspected to meet their conditions.