After decades of working in the field of OSH in Indonesia, Prof. Tan who became Professor of Public Health Unsri in 2008 is involved in various topics about Occupational Health. First, introducing the Biological (Bio) Monitoring program in Indonesia. Thirty years ago Bio Monitoring was not heard of in Indonesia even though it had long been started in the US and Europe. Almost every national agenda or training event, this grandfather of 7 grandchildren brings updates on this topic for practitioners, especially Oil & Gas and big mining corporations. There is one book published by EGC that he wrote about Bio-monitoring. Second, the Hearing Conservation Program (PKP). PKP is one of his favorite subjects that he has often introduced since the early 1990s, every time IDKI makes training events or workshops. This is because noise is often a health hazard encountered in many industrial and mining companies. Some of the companies where Prof. Tan helped develop PKP successfully are PT Total Indonesia and Panasonic Manufacturing Indonesia (PMI). Third, Industrial Hygiene (US) or Occupational Hygiene (EU) which has long developed in developed countries and is a very important OH supporting discipline. But until the end of 1990 it was still rarely heard in Indonesia. The lack of Industrial Hygiene support makes the progress of OSH in Indonesia feel lame, because this discipline focuses on assessing exposure more quantitatively. In 2003, Prof. Tan invited several friends to seriously study how to spur IH growth in Indonesia. They were the board of AHKKI at that time where Prof. Tan was the general chairman. At that time they thought colleagues in the field should be helped to recognize and control health risks in Bio-Chemical-Physical aspects that exist in the workplace. Fourth, Occupational Exposure Limits (OELs) or what is now referred to by ACGIH (2021) as Occupational Exposure Values (OEVs), is a standard or reference value for comparing the results of work environment measurements for chemical, physical and ergonomic factors. For this, each country develops OEVs according to the needs and level of development of their science and technology. However, in the international world there are three sources that are often used as references and orientations for the development of OEVs, namely ACGIH TLVs, British WELs and MAK Germany. The government itself through Menakertrans makes NAV (Threshold Value) for Indonesia. Prof. Tan was twice appointed by the Indonesian government to chair the NAB preparation process, first by the Ministry of Health in 2005 and by the Ministry of Health in 2008. Fifth, in the field of K3 education Prof. Tan works in two versions. The formal version of education is carried out at several public and private universities. For the country, Prof. Tan teaches about Keslingker (Environmental Health and Occupational Health) at Sriwijaya University at three levels of S 1, S2 and 53. For S 1 and S2 at the Faculty of Medicine and FKM for S3 at the Unsri Environmental Science Program. The training version is the one given directly to practitioners in the field. As a promoter and examiner, ProfTan has given birth to 10 doctors. There are four dissertations that are categorized as studies in the field of Work Environment, namely about Wood Dust (Dr. Chairil Zaman), Lead (Pb) (Dr. Amar Muntaha), Glyphosate Pesticides (Dr. Maksuk) and Latex Dust (Dr. Fikri Faisya)