Getting started

From blend to product

Updated October 2026

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One: write down what is actually in it, by weight Two: check it against the named substances Three: choose the format knowing what it permits Four: choose the closure, then prove it lasts Label separately, and from a different rule Keep the four answers together Work in percentages from the first batch References

Four decisions, and taking them in the wrong order is what makes people reopen the formula.

One: write down what is actually in it, by weight

Not by drop count and not by volume. Every threshold in 16 CFR 1700.14 is a percentage by weight, and for hydrocarbons it is the sum across components. You cannot test a formula you have only described qualitatively.

Two: check it against the named substances

Methyl salicylate over 5 percent. Hydrocarbons at 10 percent or more with a viscosity under 100 SUS. Turpentine at 10 percent. Petroleum distillates at 10 percent if it is sold as a lamp or lantern fuel. These are arithmetic, not judgment.

Three: choose the format knowing what it permits

A refill bottle can carry a child-resistant closure. A reed diffuser in service cannot, because its neck is open for weeks by design. If a blend crosses a threshold, the format and the formula are in conflict and one of them has to move.

Four: choose the closure, then prove it lasts

Thread match is the easy half. The standard asks the packaging to perform after real contact with the contents and after the openings and closings customary for the size, which is a question only time answers.

Label separately, and from a different rule

Hazard labeling sits in 16 CFR 1500, not 1700. A product at 10 percent or more petroleum distillates carries specified words because it can be aspirated into the lungs. Packaging and labeling are two obligations, and clearing one says nothing about the other.

Keep the four answers together

Constituents by weight, threshold result, format, closure. If any one of them changes later the others need rechecking, and a written record is what makes that a half hour rather than a guess.

Work in percentages from the first batch

A formula kept in drops or parts has to be converted before any of these tests can run, and the conversion is where mistakes enter. Recording grams and percentages by weight from the very first bench batch costs nothing then and saves recreating the arithmetic under pressure later.

References

16 CFR 1700.14, Substances requiring special packaging, under the Poison Prevention Packaging Act regulations. Paragraph (a)(3) covers liquid preparations over 5 percent methyl salicylate; (a)(7) illuminating preparations at 10 percent petroleum distillates; (a)(31) and (a)(32) hazardous substances, and drugs and cosmetics, at 10 percent or more hydrocarbons by weight and under 100 SUS at 100 F, each with an exemption for packages whose only non-child-resistant access is a spray device. law.cornell.edu

16 CFR 1500.14, Products requiring special labeling under section 3(b) of the act. Paragraph (a)(3) covers products at 10 percent or more petroleum distillates such as kerosine, mineral seal oil, naphtha and mineral spirits; (b)(3)(ii) requires the signal word "danger", the statement "Harmful or fatal if swallowed" and "Call physician immediately", because such products may be aspirated into the lungs. law.cornell.edu

Written from federal regulation, not from a formulation bench. Whether a given formula crosses a threshold in 16 CFR 1700.14 is a question about your formula, and the percentages here are the test rather than the answer. Anything on these pages is a starting point and not clearance for a specific product.