Here's something you don't see every day in the world of pesticide regulation: The National Aeronautics and Space Administration (NASA) has asked the EPA Office of Pesticide Programs for an emergency exemption from the federal pesticide law (FIFRA) to use the compound ortho-phthalaldehyde (OPA) to control the growth of "aerobic/microaerophilic water bacteria" in coolant water within several modules of the International Space Station.
Emergency exemptions are allowed under FIFRA Section 18 and EPA maintains a database of these emergency exemptions. So far in 2014, over 100 emergency exemptions have been issued, mostly to deal with newer pests (like the use of bifenthrin and dinotefuran to control the Brown Marmorated Stink Bug) and/or to provide additional tools to deal with established pests (like the use of hop beta acids to control Varroa mite in honey bee hives). Usually states are the requestors; however, other agencies will ask EPA for exemptions. USDA commonly does this.
What is unique here, of course, is the request to approve a novel PESTICIDE (i.e. not yet registered with EPA) and the fact that EPA has allowed a mere 7 days for the public to comment on this action. Emergency exemptions have a roughly 50-day time period, during which EPA will perform a risk assessment on the requested use (dietary, occupational, ecological and environmental risk assessment). Novel pesticides pose a challenge her as they may not have data to feed into a risk model; however, in this case, OPA was approved by FDA in the 1990s for use as new disinfection & sterilization technique for medical devices. Given the closed environment in the Space Station, it is important to understand the toxicity to humans and, hopefully, this was done in the 50-day review process.
The comment period for this action is open until October 22.