After an extensive search of style guides, it is evident that most DO NOT provide assistance in crafting a reference for standards, codes and other related materials. Two standards organizations, ASTM and IEEE tell you how to site their own standards within their own publication. That information is linked below. Other style guides are silent on this matter.
General rules -- the term "standard" is the generic term for all the types of documents included on this resource page.
Here are some suggestions. But, if your grade depends on how well you cite something, check with your professor!
Looks like a book? Cite it like a book! But make sure to include any numbers and codes associated with the item.
For example: ASCE/SEI 41-13 has the Library of Congress Cataloging-in-Publication included in the PDF. Use it to make a citation that follows general book citation guidelines. Add the DOI if you retrieve it online.
American Society of Civil Engineers. (2014). ASCE standard ASCE/SEI 41-13: seismic evaluation and retrofit of existing buildings. http://ascelibrary.org/doi/pdf/10.1061/9780784412855
Chicago Manual of Style:
American Society of Civil Engineers. 2014. ASCE standard ASCE/SEI 41-13: seismic evaluation and retrofit of existing buildings. http://ascelibrary.org/doi/pdf/10.1061/9780784412855
American Society of Civil Engineers. ASCE standard ASCE/SEI 41-13: Seismic Evaluation and Retrofit of Existing Buildings. 2014. Internet resource. http://ascelibrary.org/doi/pdf/10.1061/9780784412855
Are the standards included in a larger book? Cite them as individual items when possible. How you find it is not the critical issue as others may have access in different ways.
For example: The ASTM issues a book each year called the Annual book of ASTM standards. It includes over 62,000 individual standard methods in 14 sections with multiple volumes. Don't worry about what volume your standard was in. Just provide the following information.
Using the general APA (6th ed.) style:
American Society of Testing and Materials. (2014). ASTM E100-14: Standard Specification for ASTM Hydrometers. http://compass.astm.org/EDIT/html_annot.cgi?E100+14
If you are referencing a complete volume use a book reference. For example:
APA (6th ed.) American Society for Testing and Materials. (1983). Annual book of ASTM standards: Section 1. Philadelphia, Pa: ASTM.
 Title of Standard, Standard number, date.
 IEEE Criteria for Class IE Electric Systems , IEEE Standard 308, 1969.
 Letter Symbols for Quantities, ANSI Standard Y10.5-1968.