Finally, there is one other element of the test applied by the DT that needs to be refined. As framed at [64] above, it suggests that in every case, to justify any departure from the applicable guidelines, it would be essential for the medical practitioner to show that he or she had discussed with and obtained the consent of the patient to the intended departure. We are considering there, not the general duty to obtain informed consent, which is a separate, self-standing obligation, and which Dr Ang has not been charged with breaching, but rather, the distinct question of when this requirement must be met in order to justify a departure from the applicable guidelines. In our judgment, even if the medical practitioner is able to show that he considered the MOH guidelines or the limits in the product inserts and their rationales, and that the departure was objectively justifiable on the evidence, yet, in some situations, doing so will only be considered appropriate if the medical practitioner also shows that he had advised the patient of the fact of the departure and the risks inherent therein, and the patient gives his informed consent. We take this view because the limits contained in the applicable guidelines or product insert will in many cases be rooted in safety concerns of one type or another. As we have noted, the MOH guidelines represent “codifications of the standards ‘observed or adopted’ by the medical profession” (Eric Chong at [66]), and are based on the “best available evidence at the time of development”. Similarly, regulatory approval for local use of medication is granted by the HSA on the basis of an evaluation of the products’ recommended dosing regimens and recommended maximum dosages contained in their product inserts. A departure from applicable guidelines of this sort may be expected to carry with it certain risks. Even if the risk is objectively justifiable in the specific case, there is a chance that the risk may materialise and that some harm may befall the patient. Where the possibility of harm is sufficiently high and the potential consequences are of sufficient severity, it cannot be appropriate to subject the patient to the risk unless he knowingly consents to it. Additionally, proper risk management will almost invariably require that the Patient is made aware of the risks and dangers associated with the treatment in question, so as to enable him to minimise the likelihood that the harm in question would eventuate, and recognise and deal with it if it does.