Yes, if the material or method was accepted previously and remains relevant to your current tasks or projects, it is typically still appropriate to use it. However, it is essential to ensure that there have been no updates, changes in policy, or advancements that might make the previous approval obsolete. Always double-check with your supervisor or relevant department to confirm that the context has not changed and to see if there are any new guidelines to follow. This will help ensure that you are compliant with the latest standards and practices at your workplace.