27 CFR §20.92

1. (a)For each formula submitted in accordance with § 20.91 covering a toilet preparation made with S.D.A. Formula No. 39-C and containing an essential oil, the manufacturer shall submit a 0.5-ounce sample of the essential oil used in the article. The appropriate TTB officer may also require the manufacturer to submit a sample of any ingredient which is not adequately described in the formula.
2. (b)For each formula submitted in accordance with § 20.91, the appropriate TTB officer may require the manufacturer to submit a 4-ounce sample of the finished article.
3. (c)The appropriate TTB officer may, at any time, require submission of samples of:
   1. (1)Any ingredient used in the manufacture of an article, or;
   2. (2)Any article.