1.1 This specification covers dibutyl phthalate (99 % grade). 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 of Practice E29. 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 For specific hazard information and guidance, see the supplier's Material Safety Data Sheet for materials listed in this specification. 1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.