Update Hazmat codes

[cdmgtri]

Hazmat codes

US Department of Transportation Pipeline and Hazardous Materials Safety Administration

PHMSA's Online CFR (oCFR)
https://www.phmsa.dot.gov/standards-rulemaking/hazmat/phmsas-online-cfr-ocfr

• Go to oCFR Tool (under "Related Links" from left sidebar)
• Go to tab "Table of Hazardous Materials and Appendices" at top of page
• Click "Download Hazmat Table" at bottom of search form

Codes updated as of July 31st 2020

[cdmgtri]

Updates primarily consisted of cleaning up non-breaking spaces in the definitions and removing duplicate code-definition enumerations.