Military Testing
During the 40s the US Chemical Warfare Service used thousands of the US military personnel to test the effectiveness of gas masks and other protective clothing against mustard gas. This experiment could be deemed ethical because it in theory could have been used to train and prepare the troops for chemical warfare which they would probably be running into while on duty. However, mustard gas can also cause irreparable lung damage which would not help the troops so if the equipment was defective then it would not be good.
Chemical Warfare Experiments
During the period of 1950-1953 the US army sprayed different forms of unknown but potentially harmful chemicals over different United States cities. This testing was said to be done to test the dispersal patterns of chemicals to later be put to use in different chemical weapons. After this testing was conducted, even though some people protested it because they thought it should be deemed unsafe, it was found out that the amount of chemicals sprayed was at too low of a dosage to be harmful and that in fact, just by living in a highly populated area, citizens would be exposed to a higher level of more dangerous chemicals. Because of this low concentration of chemicals that really caused no harm, this testing could easily be deemed ethical.
Testing with the use of Prisoners
Between the time of 1951 and 1974 some of the most unethical testing occurred. This testing was done on inmates at the Holmesburg Prison in Pennsylvania and consisted of injecting chemicals, mainly dioxin, into the prisoners. These chemicals were used in different herbicides and were being tested on these prisoners to see if it was harmless to humans or at least see what kind of effects it would cause on the human body. In the end it caused severe skin lesions and Chloracne which consists of basically an eruption on an area of skin of blackheads, cysts and pustules. So, in the end of this experimentation period, almost every 9 out of 10 prisoners ended up being tested on, all of which ended up with mild to severe skin ailments, just to test different forms of herbicides on the human body.