if no label it defaults to nfpa 211 national fire protection ass. codes.
www.nfpa.org.
National Fire Protection Associatiion (NFPA) 211: Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances; 2006 Edition (EXCERPTS)
Reprinted with permission from NFPA 211- 2006, Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances, Copyright© 2005, National Fire Protection Association, Quincy, MA. This reprinted material is not complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety.
http://www.hpba.org/builders-designers/construction-tips-and-standards
ps, looks like its closer than 12" to combustibles, as measured thru the brick ??
12" min stove to wall if the brick has properly installed air gap.