Prohibited in the US
The FDA prohibits these substances from use in human food. Each row cites the section of 21 CFR that prohibits it. This is an explicit prohibition — not the absence of a listing, which is a different thing entirely and is shown as “not listed” elsewhere on this site.
| Substance | Status | Scope | Citation |
|---|---|---|---|
| 4,4′-Methylenebis (2-chloroanaline) | Prohibited | Indirect addition through food-contact surfaces | 21 CFR 189.280 |
| Calamus and its derivatives | Prohibited | Use in human food | 21 CFR 189.110 |
| Chlorofluorocarbon propellants | Prohibited | Use in human food | 21 CFR 189.191 |
| Cinnamyl anthranilate | Prohibited | Use in human food | 21 CFR 189.113 |
| Cobaltous salts and its derivatives | Prohibited | Use in human food | 21 CFR 189.120 |
| Coumarin | Prohibited | Use in human food | 21 CFR 189.130 |
| Cyclamate and its derivatives | Prohibited | Use in human food | 21 CFR 189.135 |
| Diethylpyrocarbonate (DEPC) | Prohibited | Use in human food | 21 CFR 189.140 |
| Dulcin | Prohibited | Use in human food | 21 CFR 189.145 |
| Flectol H | Prohibited | Indirect addition through food-contact surfaces | 21 CFR 189.220 |
| Hydrogenated 4,4′-isopropylidene-diphenolphosphite ester resins | Prohibited | Use in human food | 21 CFR 189.300 |
| Lead solders | Prohibited | Indirect addition through food-contact surfaces | 21 CFR 189.240 |
| Mercaptoimidazoline and 2-mercaptoimidazoline | Prohibited | Indirect addition through food-contact surfaces | 21 CFR 189.250 |
| Monochloroacetic acid | Prohibited | Use in human food | 21 CFR 189.155 |
| Nordihydroguaiaretic acid (NDGA) | Prohibited | Use in human food | 21 CFR 189.165 |
| P-4000 | Prohibited | Use in human food | 21 CFR 189.175 |
| Safrole | Prohibited | Use in human food | 21 CFR 189.180 |
| Thiourea | Prohibited | Use in human food | 21 CFR 189.190 |
| Tin-coated lead foil capsules for wine bottles | Prohibited | Use in human food | 21 CFR 189.301 |
What this list is not
It is not a list of substances that are unsafe, and it is not exhaustive of everything the US restricts. A substance can be absent from this page and still be unlawful in a particular food, because most US regulation works by permitting substances for named uses rather than by prohibiting them by name.
Colour additives whose listing has been revoked are a separate case and are shown above where we hold them. Provisional listings under 21 CFR 82 are not yet represented; see the known gaps in our method.