unflammable

From un- +‎ flammable.

unflammable (comparative more unflammable, superlative most unflammable)

1. Not flammable.
   • 1999, Maria Csuros, Csaba Csuros, Microbiological Examination of Water and Wastewater, Lewis Publishers, →ISBN, page 111:

     Refrigerators used for flammables should be unflammable material storage units or explosion-free.

   • 2008, ACI Materials Journal, page 21:

     Many of the silane-based penetrants are alcohol- or solvent-based and flammable. The nature of AAS used in this study is unflammable and unvolatile, which allowed for construction safety;

   • 2011, Bo Ersson, Lars Rydén, Jan-Christer Janson, “Introduction to Protein Purification”, in Protein Purification: Principles, High Resolution Methods, and Applications (Wiley Series in Methods of Biochemical Analysis), 3rd edition, Wiley, page 8:

     The main advantage of PEG over organic solvents is that it is more easily handled. It is unflammable, not poisonous, uncharged, and relatively unexpensive.

• nonflammable
• noninflammable
• uninflammable