How could an employee become exposed to hydrogen peroxide using HPV systems? What can you do to prevent this from happening?

First and foremost, for an employee to become exposed to hydrogen peroxide vapor during room decontamination, they would have to ignore the safety protocols and/or breach the containment area. This should never happen. Unfortunately, no matter how thorough the safety procedures and training, or how foolproof the system, we see employees disregard or defeat them too often. Sometimes it is out of ignorance, a new employee, or one from a different department that was unaware of the process. Other times it might be a hard-working, conscientious employee pressured with a deadline or short-cutting to get more done in a day.

The only other potential scenario for employee exposure would be a malfunctioning system, such as a leak or a faulty reading from a sensor. HPV systems usually incorporate sensors to monitor the levels of hydrogen peroxide during the conditioning and maintenance phases and to indicate the end of the purge cycle. In addition, there are personal monitors and instruments that must be used to check areas prior to re-entry or use.

So, how do we prevent exposures from occurring? First, ensure all employees that will operate the HPV system receive the recommended training from the manufacturer. Then provide awareness training (to the appropriate level of detail) for employees that may work in the enclosure(s) or area(s) under decontamination. Finally, make sure the area is secured, well-marked, or otherwise clearly designated as a “No Entry” area until decontamination is complete and the purge verified. For potentially malfunctioning equipment, the operators must thoroughly inspect the equipment before use. Check seals, sensors, and controls according to manufacturer’s instructions. Know how to calibrate and operate the monitoring equipment and have spare sensors on hand. Most importantly, make sure the monitors are used for each decontamination project and that areas or enclosures are cleared before re-entry or use.
  
Safe use of HPV systems is a matter of training employees, following the manufacturer’s procedures, and proper use of available monitoring sensors. Knowledge of the HPV cycle and understanding the application equipment and the monitoring instruments can prevent unwanted employee exposures and possible injuries. Manufacturers have developed and refined safe operating protocols over the years. Most offer on-site multi-day training on proper set up, operation, and safeguards.

From HPV-Redux by the Safety Guys