This method has not been reapproved since 2014 and therefore requires renewal per ASTM procedures. It was reviewed by practitioners and users and found to be current and relevant. Editorial changes and updates were made to be consistent with current practices, to improve clarity or consistency, and new references were added. One of these updates to include references to LED lighting and a discussion of data where toxicity testing was compared among variable lighting sources. Note that reference numbers will be listed sequentially in the published version of this guide.