Ammonia Dilution Test for
Effectiveness in Developing Blueprint Paper

The purpose of this test was to see if it would be possible to dilute the ammonia used to develop the blueprint paper used in the Ritter Ultraviolet Experiment. If the ammonia could be diluted with water, this would reduce the amount of ammonia fumes to which students would be exposed and reduce the toxicity of the developing fluid.


The materials used in the experiment (left) and a strip of blueprint paper after being exposed to the vapors of 100% ammonia for 30 seconds. Can diluted ammonia be used to produce a similar result?

To test the strength of ammonia needed to develop blueprint paper, I mixed full strength household ammonia with various amounts or either cool or warm water. The mixtures were poured into a small dish (3.5 cm high) to a depth of 1 cm. Strips of blueprint paper were then placed (color side down) on top of the dish and covered to keep most of the ammonia vapor from escaping - this makes the blueprint paper develop more quickly and reduces fumes. I simply used a CD jacket to cover the dish. The paper strips were developed for either 30, 60, or 90 seconds.


Strips of blueprint paper after exposure to vapors from a mixture of 50% ammonia and 50% cool tap water. The exposure times were 30 seconds (left), 60 seconds (middle) and 90 seconds (right). Exposure for 90 seconds produced results close to that of exposure to fumes of 100% ammonia for 30 seconds.


Strips of blueprint paper after exposure to vapors from a mixture of 50% ammonia and 50% warm tap water. The exposure times were 30 seconds (left) and 60 seconds (right). Exposure for 60 seconds produced even greater blueprint paper development than that caused by exposure to fumes of 100% ammonia for 30 seconds.


Strips of blueprint paper after exposure to vapors from a mixture of 25% ammonia and 75% warm tap water. The exposure times were 30 seconds (left) and 60 seconds (right). Exposure for 60 seconds produced results similar to that of exposure to fumes of 100% ammonia for 30 seconds.


A strip of blueprint paper after exposure to vapors from a mixture of 20% ammonia and 80% warm tap water for 60 seconds. This also produced results similar to that of exposure to fumes of 100% ammonia for 30 seconds.


Strips of blueprint paper after exposure to vapors from a mixture of 10% ammonia and 90% very warm tap water. The exposure times were 60 seconds (left) and 90 seconds (right). Exposure for 90 seconds produced results similar to that of exposure to fumes of 100% ammonia for 30 seconds.

CONCLUSION: Diluting ammonia with warm water allows you to develop blueprint paper in less time than does diluting ammonia with cool water. You can get similar amounts of blueprint paper development when it is exposed to vapors from the following mixtures and for the following development times:


100% Ammonia for 30 seconds
50% Ammonia + 50% Cool Water for 90 seconds
50% Ammonia + 50% Warm Water for 60 seconds
25% Ammonia + 75% Warm Water for 60 seconds
60% Ammonia + 80% Warm Water for 60 seconds
10% Ammonia + 90% Warm Water for 90 seconds

This experiment shows that you can dilute ammonia as much as 90% by combining it with warm water and still develop blueprint paper in a reasonable amount of time, with a great reduction in ammonia fumes and toxicity.