JURNAL PENDIDIKAN DAN PENGAJARAN Volume 54 Nomor 1 2021, pp 190-198 E-ISSN: 2549-2608; P-ISSN: 2301-7821 DOI: http://dx.doi.org/10.23887/jpp.v54i1 181 Basic Chemistry Practicum Handbook with Occupational Health and Safety (K3) to Prevent Work Accidents in Laboratory: Validity and Feasibility I Ketut Sudiana 1* , I Wayan Suja 2 , I Dewa Ketut Sastrawidana 3 , I Nyoman Sukarta 4 1,2,3,4 Ganesha University of Education, Singaraja, Indonesia *Corresponding author: sudi.ana@undiksha.ac.id Abstract First year students of the Chemistry Education Study Program have some problems in practicum because the students' basic laboratory skills are low. The current practicum guide is not sufficient to provide information on basic skills for working in the laboratory. This condition causes students to have problems practicum and there is a potential risk of accidents. This study aims to produce a handbook for Basic Chemistry I with Occupational Health and Safety (K3) which is feasible to be implemented in Basic Chemistry Practicum I. This research was a Research and Development (R&D) with a 4-D development model, consist of 4 main stages, Define, Design, Develop and Disseminate. The research was limited to the development stage, which ended in the legibility test. Based on expert assessment the results showed that the handbook for Basic Chemistry Practicum I with K3 was very valid in terms of content (3.75), language (3.70), and media (3.6) from a maximum score of 4. The results of the readability test from 9 students showed that all students gave clear assessments. They understood the contents and guidelines for practicum on Basic Chemistry 1 with K3 very well. The conclusion of this study is Basic Chemistry Practicum I Handbook with K3 content is valid to be implemented from the aspects of content, presentation, language, media, and readability. Keywords: Practicum Guide, Basic Chemistry, Occupational Health and Safety History: Received : 24 August 2020 Revised : 1 September 2020 Accepted : 26 September 2020 Published : 25 April 2021 Publisher: Undiksha Press Licensed: This work is licensed under a Creative Commons Attribution 3.0 License Introduction Chemistry is a branch of science that has characteristics based on experiments. In chemistry learning, understanding concepts and theories need practicum as a direct learning experience. In chemistry there are two things that closely related, chemistry as a product (chemical knowledge in the form of facts, concepts, theories, and principles) and the process (scientific work) (Effendi-Hasibuan, Fuldiaratman, Dewi, Sulistiyo, & Hindarti, 2020; Hairida, 2018; Maison et al., 2020). Both of these things can be achieved by students through practicum. Practicum guide is needed to make practicum carried out well or following the objectives to be achieved. A practicum guide is a facility provided by lecturers/teachers so that students can learn and work well (Maison et al., 2020; Sumarti, Nuswowati, & Kurniawati, 2018). Laboratory as a place for practicum takes high seriousness, although it depends on the guidelines made by teachers or lecturers and students do the work (Hill Jr & Finster, 2016; WHO, 2011). They must work with the chemicals they use safely. A laboratory is a place for teaching staff (lecturers and teachers), students, and laboratory workers to make experiment with chemicals, glassware, and special tools. The use of these chemicals and tools has work