Chemical descriptors capitalization

Do not capitalize lowercase chemical descriptors hyphenated to chemical names when they are at the beginning of a sentence. 

When the first word of a sentence is a roman chemical descriptor that is not part of a chemical name, capitalize it. 

Do not capitalize lowercase chemical descriptors in titles and headings, but do capitalize the first letter of the English word. 

Do not capitalize chemical names or nonproprietary drug names unless they are at the beginning of a sentence or are in a title or heading. In such cases, capitalize the first letter of the English word, not the locant, stereoisomer descriptor, or positional prefix. (See Chapter 12, Names and Numbers for Chemical Compounds .)... 

The names of chemical compounds may consist of one or more words, and they may include locants, descriptors, and syllabic portions. Locants and descriptors can be numerals, element symbols, small capital letters, Greek letters, Latin letters, italic words and letters, and combinations of these. Treat the word or syllabic portions of chemical names just like other common nouns use roman type, keep them lowercase in text, capitalize them at the beginnings of sentences and in titles, and hyphenate them only when they do not fit completely on one line. 

---