This research project investigates communication between international teaching assistants and their undergraduate students in university-level chemistry labs. During the fall semester, introductory-level chemistry lab sections of three experienced non-native speaking teaching assistants and their undergraduate students were observed. Digital audio and video recordings documented fifteen hours of lab communication, focusing on the activities and interactions in the first hour of the chemistry laboratory sessions. In follow-up one-on-one semi-structured interviews, the participants (undergraduates, teaching assistants, and faculty member) reviewed interactions and responded to a 10-