Is Liquid Rubber Waterproof Sealant environmentally friendly? Yes, it is a water based product containing no solvents or VOC's (volatile organic compounds). Related articles The black surface turns brown when wet? Can I build my final membrane all at once? How do I cover gaps and cracks? Can Waterproof Sealant be put on tarred surfaces? How should I prepare the surface before applying Waterproof Sealant? Comments 0 comments Please sign in to leave a comment.