Figure 1-10 Mistake-Proofing the Design of Health Care Processes - Figure 1.10. Smell as a sensory alert has been used in natural gas delivery. An additive, mercaptan, is used to create an unpleasant smell, so that gas leaks can be detected23,24 Return to Document Current as of May 2007 Internet Citation: Figure 1-10: Mistake-Proofing the Design of Health Care Processes -. May 2007. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/professionals/quality-patient-safety/patient-safety-resources/resources/mistakeproof/mistakefig1-10.html