The IP rating of an actuator is a good indicator of how suitable it is for various environments including wash down. The minimum to consider out door or light wash down use is IP65 which can stand low pressure water jets from any direction. The Electrak 2 and 10 are both IP65 rated.  The next level is IP67 which will keep out water when submerged in 1m of water and NOT running. Finally, IP69K is the best and will keep out water from high pressure jets and immersion. The Electrak HD and Max Jac both meet the standards of IP69K.