Norm ASTM D4734-07
1.1 This specification covers benzene-545.
1.2 The following applies to all specified limits in this standard: for purposes of determining conformance with this standard, an observed value or a calculated value shall be rounded off "to the nearest unit" in the last right-hand digit used in expressing the specification limit in accordance with the rounding-off method in Practice E 29.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 Consult current OSHA regulations, supplier's Material Safety Data Sheets, and local regulations for all materials used in this specification.