National List of Allowed and Prohibited Substances
The USDA-maintained list of synthetic substances allowed in organic production, and the natural substances prohibited. Lives in NOP §205.601 through §205.606.
The National List of Allowed and Prohibited Substances — usually called just the National List — is the USDA-maintained registry that defines which substances may and may not be used in organic production and handling.
Why it exists
The default rule under organic standards is that natural substances are allowed and synthetic substances are prohibited. The National List is the set of exceptions to that rule, in both directions:
- Specific synthetic substances that ARE allowed in organic production (e.g. some forms of copper for plant disease control)
- Specific natural substances that are NOT allowed (e.g. arsenic, strychnine, tobacco dust)
How it's organized
Six sections, each at its own NOP citation:
| Section | Coverage |
|---|---|
| NOP §205.601 | Synthetic substances allowed for use in organic crop production |
| NOP §205.602 | Nonsynthetic substances prohibited for use in organic crop production |
| NOP §205.603 | Synthetic substances allowed for use in organic livestock production |
| NOP §205.604 | Nonsynthetic substances prohibited for use in organic livestock production |
| NOP §205.605 | Nonagricultural (nonorganic) substances allowed as ingredients in or on processed products |
| NOP §205.606 | Nonorganically produced agricultural products allowed as ingredients in or on processed products labeled as "organic" |
How operations use it
Every input on the operation — soil amendments, foliar sprays, livestock medications, processing aids — must be checked against the National List before use. Many materials require additional certification (e.g. OMRI-listed) to confirm they meet the National List criteria.
The OSP includes a complete list of inputs to be used, and the certifier reviews each against the National List before approving the plan.
Updates to the list
The list is amended periodically by the USDA after recommendations from the National Organic Standards Board (NOSB). Substances cycle on and off — methionine for poultry feed, for example, has had its allowed-form definition revised multiple times. Operations must use the current version of the list, not the version that was in effect when the OSP was first written.
Cited regulations
Linked to the current eCFR text of 7 CFR Part 205. Reviewed before publication.
QO Editorial Team
Quick Organics
Quick Organics' editorial team writes about USDA organic certification, the Organic System Plan, and the daily realities of running a certified organic operation. Material is reviewed against the current eCFR text of 7 CFR Part 205 before publication.