Healthcare Safety Investigation Branch (HSIB) report on the inadvertent administration of an oral liquid medicine into a vein. This report indicated the importance of using human factors in the investigation process. The investigation reviewed the effectiveness of the current processes for the storage of medicines, equipment design, and the prescribing, preparation, checking and administration of medication. It also considered the contextual, environmental and human factors that influenced the inadvertent administration of an oral solution into a vein. The effectiveness of current processes for implementation of local safety standards for invasive procedures was also considered. A human factors expert was involved in the investigation and a dedicated report was written based on the evidence reviewed, a reconstruction of the event and a simulation of what should have happened.