Format: 

Authoring Agency. Title of Standard. Publishing Agency, Day Month Year. Standard Number. Database Name or Title of Non-Publisher Website, DOI or URL. Accessed Day Month Year.

Authoring Agency. Title of Standard. Publishing Agency, Day Month Year, URL or DOI (when accessed from the publisher's website). Standard Number.

Authoring Agency. Title of Standard. Publishing Agency, Day Month Year. Standard Number.

Examples: 

ASTM International, Subcommittee D13.51. ASTM D629-15 Standard Test Methods for Quantitative Analysis of Textiles. Mar. 2015, doi:10.1520/D0629-15.

In-text: (ASTM International, Subcommittee D13.51)

Electrodes, Graphite, Spectrometric Grade. United States, Department of Defense, Defense Logistics Agency, 16 Sep. 2013. MIL-DTL-8971F. Engineering360, IEEE, standards.globalspec.com/std/1631456/dla-mil-dtl-8971f.

In-text: (Electrodes)

Notes: 

As with other electronic sources, omit the http:// or https:// from the citation (MLA 110). Provide the authoring agency, standard title, publishing agency, and date of publication in the first part of the citation. If the publishing agency is already captured by the title of the standard (e.g. in the first example the standard was published by ASTM), you can omit the publisher (MLA 42). Similarly, if the authoring agency is the same as the publisher, which is often the case, you can omit the agency name (MLA 25). In the first example, ASTM International has already been captured by the title, but is still listed as the author since a specific subcommittee is included and not captured by other parts of the citation. If you accessed the standard directly from the publisher's website or standard library (e.g. ASTM Compass), provide the URL or DOI immediately after the publisher preceded by a comma. Otherwise, provide the name of the website or repository (e.g. EverySpec), along with the DOI or URL as a separate piece of information at the end of the citation (see second example). If the standard number is not captured in the title of the citation, you should provide it after the publishing date or URL, but before the repository information (MLA 53).

Source:

This source type is not covered by the MLA Handbook (8th ed.)