Creating awareness of environmental sustainability issues through formal education may be an effective way to help citizens deal with these issues. Teachers, however, have not been sufficiently trained on how to teach with sustainability concerns in mind. For this study, a purposively selected group of six chemistry teachers was exposed to an online professional development intervention (PDI) whose content draws on collective pedagogical content knowledge (cPCK) about the extraction of metals and mining as related to environmental sustainability. This paper reports on a study that explores the transfer of knowledge from cPCK to personal PCK (pPCK), and from pPCK to enacted PCK (ePCK). Data were collected using a pre- and post-PDI questionnaire, interviews and a lesson plan template. These tools were used to capture the teachers' pPCK and ePCK. During the analysis of the data, a validated PCK rubric and a master content representation created by experts were used. The PCK components of knowledge of curricular saliency, student thinking and conceptual teaching strategies constituted the lens through which the researchers investigated the chemistry teachers' PCK. The findings of this study revealed that the intervention enhanced the quality of the teachers' ePCK about extraction of metals, by informing their pPCK. It also showed that despite being exposed to the same intervention, the PCK of all the teachers did not develop to the same extent. Four of the six participants showed a positive gain in the quality of their PCK across all three components, while the other two only showed a positive gain on two of the three components. The differences in PCK development within the context of chemistry teaching were attributed to the presence of amplifiers and filters. The study contributes to both theory and practice, highlighting the need for research-informed continuous professional development of teachers in education for sustainability and suggesting ways to infuse sustainability into their teaching of chemistry.