Calibration Standard 4A for EPA 200.7 is a certified reference material traceable to NIST and manufactured in accordance with stringent quality assurance guidelines. One year expiration date. COA and MSDS are included.
Contains Hg 200 ug/mL, Cr, Zn 500 ug/mL each, Al 1000ug/mL, stabilized in 5% v/v nitric acid. 125 mL bottle.