Prof du Plessis holds a BSc, BSc Hons (Physiology), MSc (Physiology) and PhD (Occupational Hygiene) degrees. He received a Y2 research rating from the National Research Foundation in 2014. His teaching-learning experience is in physiology, toxicology and occupational hygiene. To date he has supervised 30 Masters and PhD students and authored more than 30 papers published in accredited journals. His research focus and expertise is on exposure to chemical stressors in the workplace. This includes assessing the potential risk of exposure, assessing actual levels of exposure and controlling the level of exposure. Another research interest is regulatory toxicology, in particular occupational exposure limits.