Meets actual ASTM C-309 moisture retention. Pentra-Sil® (HD+C) is a water-based, clear, dissipating membraneforming curing compound, hardener and densifier. This single component application forms a tougher, abrasion resistant surface compared to traditional methods requiring post-densification (28 days later). Excellent for commercial and industrial concrete floors that need long-term protection against heavy wear and abuse, moisture, dirt and grime buildup. This earth friendly / bio based compound contains no solvents and has a VOC content<100g/L making it compliant in all regions of the United States.