... acid, hydrogen borate, boracic acid, orthoboric acid and acidum boricum, is a weak acid of boron 1.Used in producing optical glass, acid ... additive, lubricant, thermal oxidationstabilizer and fire retardant.5.Used in the production of borate.6. ... the customer's requirement ItemIndexFirst gradeSecond gradeBoric acid(%)≥99.5%≥96.5%Water insolubles(%)≤0.05%≤0.15% ... )(%)≤0.003%≤0.005% 99.5%boric acid H3BO3