Well the chemists didn't reply so I did a little Googling and found the following info I hope it gives some comfort about washing
Un-ionized ammonia (NH3) is a colorless gas at standard temperature and pressure. A pungent odor
is detectable at levels above 50 ppm (NRC, 1979). Ammonia is very soluble in water at low (acidic) pH.
Ammonia levels in zero-salinity surface water increase with increasing pH and temperature .... At low pH and temperature, ammonia combines with water to produce an ammonium ion (NH4+) and a hydroxide ion (OH-). The ammonium ion is non-toxic and not of concern to organisms.
Above a pH of 9, un-ionized ammonia is the predominant species (Morgan et al., 1981). The un-ionized ammonia (NH3) can cross cell membranes more readily at higher pH values.
Ammonia remains in the atmosphere only 5 - 10 days before being deposited or chemically altered. The fate of atmospheric ammonia is largely a function of global location and weather
conditions. If ammonia is introduced into a pristine water system (neutral pH or slightly less), it is readily converted to nitrate by nitrification and becomes harmless to aquatic life
(NRC, 1979). (For more information, refer to nitrification in the nitrate-nitrite section
Ammonia often serves as the primary or secondary source of nitrogen for plant life. While some plants prefer ammonia to other forms of nitrogen, other plants prefer nitrate but can assimilate gaseous ammonia if necessary (NRC, 1979).