Engineering controls are physical or mechanical measures that eliminate or minimise generation of chemicals, suppress or contain them or limit contamination from spills: intrinsically safe equipment in hazardous areas, robots to reduce operator exposure, partially enclosed and ventilated spray booths or fume cupboards, enclosed ventilation booths and local exhaust ventilation near the point of release. Ventilation must be designed for the purpose, avoid recirculation unless contamination is detected and controlled, serve the specific space or not increase exposure if linked, suit the chemicals (extract heavy vapours at the lowest point with fresh air from above), use ducting resistant to the vapours with fire dampers and flashback protection where needed, discharge away from air intakes, treat exhaust as needed, and be checked in planned maintenance so vents stay clear. Systems should follow technical standards and be installed and maintained by qualified people. Local exhaust beats general dilution for highly toxic contaminants, mechanical ventilation should keep storage rooms under negative pressure to adjoining spaces, and natural ventilation suits only small amounts of low toxicity contaminants.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.