The production of biodiesel is often criticized because of the use of eatable oils like palm oil, soybean oil or rape seed oil. Therefore, researchers from Austria, South Korea, and Germany investigated waste oils from different production processes. In detail, fish oil and rubber tree oil were transesterified with methanol to produce biodiesel. These highly unsaturated biodiesels were tested in a single cylinder diesel engine with respect to their regulated and non-regulated emissions and their health effects. Additionally, the biodiesels were partly hydrogenated to improve the oxidation stability.