Not officially, but yes. Gas mask bags were used for a range of other tasks. As the M39 borsa tattica was used mainly as a back pack (you rarely see it carried as a tascapane in photos), the M33 (if issued) or the M35 gas mask bag was often used as a ditty bag. This was common in most armies. Soldiers would throw away their gas masks (or store them) and use the container for other items.