OSHA permits the use of a self-contained eyewash unit IF that unit can supply 15 minutes of flushing fluid, but it also must provide the required flow rate of .4 gallons per minute. A 16 gallon self-contained unit would likely be able to provide 15 minutes of flushing at the required flow rate, but must be verified through testing. It would be compliant provided all other eyewash requirements were met.