Because they are optimized for continuous hospital use, they favor rectangular designs, require demanding maintenance regimens, and are costly to operate. (A properly calibrated medical-grade autoclave uses thousands of gallons of water each day, independent of task, with correspondingly high electric power consumption.) In research Autoclaves used in education, research, biomedical research, pharmaceutical research and industrial settings (often called "research-grade" autoclaves) are used to sterilize lab instruments, glassware, culture media, and liquid media. Research-grade autoclaves are increasingly used in these settings where efficiency, ease-of-use, and flexibility are at a premium. Research-grade autoclaves may be configured for "pass-through" operation. This makes it possible to maintain absolute isolation between "clean" and potentially contaminated work areas. Pass-through research autoclaves are especially important in BSL-3 or BSL-4 facilities. Research-grade autoclaves—which are not approved for use in sterilizing instruments that will be directly used on humans—are primarily designed for efficiency, flexibility, and ease-of-use. They display a wide range of designs and sizes, and are frequently tailored to their use and load type. Common variations include either a cylindrical or square pressure chamber, air- or water-cooling systems, and vertically or horizontally opening chamber doors (which may be electrically or manually powered). In 2016, the Office of Sustainability at the University of California, Riverside (UCR) conducted a study of autoclave efficiency in their genomics and entomology research labs, tracking several units' power and water consumption. They found that, even when functioning within intended parameters, the medical-grade autoclaves used in their research labs were each consuming 700 gallons of water and 90 kWh of electricity per day (1,134MWh of electricity and 8.8 million gallons of water total), because they consumed energy and water continuously, even when not in use. UCR's research-grade autoclaves performed the same tasks with equal effectiveness, but used 83% less energy and 97% less water. Quality assurance There are physical, chemical, and biological indicators that can be used to ensure that an autoclave reaches the correct temperature for the correct amount of time. If a non-treated or improperly treated item can be confused for a treated item, then there is the risk that they will become mixed up, which, in some areas such as surgery, is critical. Chemical indicators on medical packaging and autoclave tape change color once the correct conditions have been met, indicating that the object inside the package, or under the tape, has been appropriately processed. Autoclave tape is only a marker