The NASA Spaceflight article Extended Russian EVA complete – conducts satellite deployments says:
The first order of the day was for Ryazanskiy to head into the manual deployment of five nanosatellites from a ladder outside the airlock, following set up tasks including the hosting of a Go-Pro camera. (emphasis added)
The satellites, each of which has a mass of about 11 pounds, have a variety of purposes.
One of the satellites, with casings made using 3-D printing technology, will test the effect of the low-Earth-orbit environment on the composition of 3-D printed materials. Another satellite contains recorded greetings to the people of Earth in 11 languages.
It sounds like they were just tossed by hand into space. What are the orbital mechanical consideration behind "hand-launching" things from the ISS? What keeps it from coming back and hitting you in the back of the head 93 minutes later? (or from the side 46.5 minutes later for that matter)
Seriously, are there rules and constraints applied to launching satellites by hand from the ISS so that there is very little risk of it intercepting the ISS at some point later in time? Certain directions and/or speeds only?
More background on the nanosatellites:
A third satellite commemorates the 60th anniversary of the Sputnik 1 launch and the 160th anniversary of the birth of Russian scientist Konstantin Tsiolkovsky.