Is mixing ammonia and bleach spray in the same parcel of air considerably dangerous to health?
This information is only for academic and educational purpose only. Please never ever try to mix ammonia and bleach.

Mixing bleach and ammonia is extremely dangerous, since many toxic vapors (nitrogen-chlorine species) will be produced. The primary toxic chemical formed by the reaction is chloramine vapor and hydrazine. (very, very toxic).

The following is the list of chemical species produced by the reaction:


$\ce{NH3}$ = ammonia
$\ce{HCl}$ = hydrochloric acid
$\ce{NaOCl}$ = sodium hypochlorite
$\ce{Cl2}$ = chlorine gas
$\ce{NH2Cl}$ = chloramine
$\ce{N2H4}$ = hydrazine
$\ce{NaCl}$ = sodium chloride or salt (non-toxic)
$\ce{H2O}$ = water (non-toxic)


The bleach decomposes to form hydrochloric acid:

$$\ce{NaOCl → NaOH + HOCl}$$

$$\ce{HOCl → HCl + [O]}$$

And then the ammonia and chlorine gas react to form chloramine, which is released as a vapor:

$$\ce{NaOCl + 2HCl → Cl2 + NaCl + H2O}$$

$$\ce{2NH3 + Cl2 → 2NH2Cl}$$

If ammonia is present in excess, toxic and potentially explosive liquid hydrazine may be formed.

$$\ce{2NH3 + NaOCl → N2H4 + NaCl + H2O}$$

References:


http://chemistry.about.com/od/toxicchemicals/a/Mixing-Bleach-And-Ammonia.htm
http://home.onehowto.com/article/what-happens-when-you-mix-bleach-and-ammonia-7512.html