item

Standard

B₂O₃

48.5%Min

NA₂O

21.5%Min

SO₄

0.061%Max

Cl

0.00015%Max

Fe

0.0003%Max

Water Insoluble Matter

0.013%Max

Item

Super-Grade

First-Grade

Na₂B₄O₇·10H₂O content

99.5% Min

95% Min

CO₂ content

0.1% Max

0.2% Max

Insoluble in water

0.04% Max

0.04% Max

SO₄^2- content

0.1% Max

0.2% Max

Cl^- content

0.03% Max

0.05% Max

Fe content

0.002% Max

0.005% Max

B₂O₃

36.3% Max

36.3% Max