Yes, its safety when used as a food additive has been approved by the U.S. Food and Drug Administration (FDA), European Food Safety Authority (EFSA),  Joint FAO/WHO Expert Committee on Food Additives (JECFA), as well as other authorities.

FDA
Calcium propionate is an antimicrobial agent used in food with no limitation other than current good manufacturing practice. It is generally recognized as safe (GRAS) as a direct human food ingredient in baked goods, cheeses, confections and frostings, gelatins, puddings, and fillings and jams and jellies. (2)

EFSA
Calcium propionate (E282) is listed in Commission Regulation (EU) No 231/2012 as an authorised food additive and categorized as “additives other than colours and sweeteners” (3)

Safety Re-evaluation in 2014
After the studies of genotoxicity, carcinogenicity, reproductive & developmental toxicity and other researches, EFSA concluded that “it would not be a safety concern from the maximum concentrations of propionic acid and its salts at their currently authorised uses and use levels as food additives.” (4)

Authorised Uses And Use Levels
Its application is listed together with propionic acid (E280), sodium propionate (E281) and potassium propionate (E283). Its maximum permitted levels (MPLs) ranging from 1000 to 3000 mg/kg in foods. The following foods may contain with it (5):

Ripened cheese
Prepacked sliced bread and rye bread, energy-reduced bread; partially baked prepacked bread; prepacked rolls, tortilla and pitta   
prepacked fine bakery wares

http://www.chinafooding.com/Calcium_Propionate