Truth in Marketing
Federal Trade Commission
Truth in Advertising
Here in the USA we have a federal “Truth in Advertising” law that says an “ad must be truthful, not misleading, and, when appropriate, backed by scientific evidence.”
Federal Trade Commission enforces these truth-in-advertising laws.
I couldn’t find the actual law so here is a summary
CHRON: The Federal Truth in Advertising Law
I would argue that products that do not disclose their ingredients are “not telling the truth” about their products. This especially applies to products made from toxic materials that are not disclosed, giving a false impression to consumers that their toxic products are safe to use.
Therefore, to me, truth-in-advertising includes truthful disclosure of ingredients.