Is mortar toxic?
 

Does anyone know if mortar is toxic to leos?

Here is a bit on exposure in humans from a Material Safety Data Sheet (http://www.rapidset.com/MortarMix_MSDS.asp). I would assume that the effects on the eyes and upper respiratory system would be similar in humans and leos.

Acute - Dry cement, when combined with body moisture and wet cement, especially as an ingredient in plastic (unhardened) concrete, can dry the skin and cause alkali burn. Cement dust can irritate the eyes and upper respiratory system.
Chronic - Cement dust can cause inflammation of the lining tissue of the interior of the nose and inflammation of the cornea. Hypersensitive individuals may develop an allergic dermatitis. (Cement may contain traces of hexavelent chromium).

If you are looking for something to put tile in an enclosure, I just did tons of research on the subject before I created a mosaic tile bottom for one of my tanks. There is non-toxic grout that comes in a variety of colors at any craft store.

Ok thanks. The mortal I did plan on using was the tile grout mortar. I saw a styrofoam hideout which was covered with mortar in Trempers "bible" and wanted to create something similar.