9 CFR 424.21 and 424.22

Ingoing nitrite

Parts per million of sodium nitrite going into the meat, from the mass of cure mixture, its stated nitrite content and the green weight, checked against the limit for the product class.

This is the calculation the regulation is written around. The chart in 9 CFR 424.21(c) states its limits as a weight of curing salt against a weight of meat, and 9 CFR 424.22(b) states the bacon limits directly in parts per million on the skin-free green weight. Both are ingoing figures: measured against the meat as it goes into the cure, not against the finished product.

The nitrite content of the cure mixture is an input rather than an assumption. This site does not hard-code a figure for it, because 9 CFR 424.21(c) requires that the specific nitrite content of a supply be known and clearly marked on it. Read the container.

The limits this checks against

Ingoing sodium nitrite by product class, 9 CFR
Product class	ppm	Kind	Citation
Chopped or comminuted meat, meat byproduct or poultry	156.25	Maximum	9 CFR 424.21(c), curing agents
Dry cure applied to whole muscle	625.00	Maximum	9 CFR 424.21(c), curing agents
Bacon, injected or massaged	120.00	Prescribed	9 CFR 424.22(b)(1)
Bacon, immersion cured	120.00	Maximum	9 CFR 424.22(b)(2)
Bacon, made with dry curing materials	200.00	Maximum	9 CFR 424.22(b)(3)
Finished product, all classes	200	Maximum	9 CFR 424.21(c)

How the two derived figures were obtained

Chopped or comminuted meat, meat byproduct or poultry

156.25 ppm

The chart permits 1/4 oz of sodium or potassium nitrite to 100 lb of chopped meat. 0.25 oz = 7.0873808 g; 100 lb = 45359.237 g; 7.0873808 / 45359.237 = 1.5625e-4, which is 156.25 ppm. Both conversions are exact by definition, so this figure is exact.

9 CFR 424.21(c), curing agents

Dry cure applied to whole muscle

625.00 ppm

The chart permits 1 oz of sodium or potassium nitrite to 100 lb of meat in a dry cure. 1 oz = 28.349523125 g; 100 lb = 45359.237 g; 28.349523125 / 45359.237 = 6.25e-4, which is 625 ppm.

The same chart entry caps the FINISHED product at 200 ppm of nitrite calculated as sodium nitrite. A dry cure may go on at up to 625 ppm because most of it is never absorbed and because the product loses weight; the finished-product cap still applies.

9 CFR 424.21(c), curing agents

The figure this site will not give you

9 CFR 424.21(c) also permits 2 lb of nitrite to 100 gallons of pickle at a 10 percent pump level. This site does not convert that into ppm. Doing so requires the density of the pickle, which the regulation does not state and which varies with how much salt and sugar are in it. The commonly quoted answer of 200 ppm falls out only if you assume 100 gallons of pickle weighs exactly 1,000 lb. That assumption may be reasonable; it is not in the regulation, and this site does not present assumptions as derivations.

Calculate

Meat, green weight (g)

Cure mixture applied (g)

Nitrite in that mixture (% by weight)

Read this off the container. 9 CFR 424.21(c) requires that the specific nitrite content of a supply be known and clearly marked.

Check against

9 CFR 424.21(c), curing agents

Ingoing sodium nitrite

156.3 ppm

Working

nitrite mass  = cure mass x nitrite fraction
              = 2.50 g x 6.2500 / 100
              = 0.156250 g

ingoing ppm   = nitrite mass / meat mass x 1,000,000
              = 0.156250 / 1,000.0 x 1e6
              = 156.25 ppm

limit         = 156.25 ppm  (9 CFR 424.21(c), curing agents)
cure at limit = 2.500 g for 1,000.0 g of meat

Within the 156.25 ppm maximum in 9 CFR 424.21(c), curing agents.

Separately, 9 CFR 424.21(c) caps the finished product at 200 ppm of nitrite calculated as sodium nitrite. That is a different measurement, taken on a different weight, and this calculator does not predict it: how much nitrite survives depends on the cure, the pH, the reductants present and how long the product is held.

Worked example

2.5 g of a cure mixture stated at 6.25 percent sodium nitrite, applied to 1,000 g of meat.

nitrite mass = 2.50 g x 6.25 / 100 = 0.156250 g
ingoing ppm  = 0.156250 / 1,000 x 1,000,000
             = 156.25 ppm

against the comminuted maximum of 156.25 ppm: within

Potassium nitrite equivalents

Sodium nitrite, ppm	Potassium nitrite, ppm	Citation
120	148	9 CFR 424.22(b)(1)
100	123	9 CFR 424.22(b)(1)(ii)(A)
200	246	9 CFR 424.22(b)(3)

Source: Electronic Code of Federal Regulations, Title 9, parts 424 and 319, as in force on 1 January 2026. Retrieved 4 September 2026.

What this does not tell you

The finished-product cap of 200 ppm in 9 CFR 424.21(c) is a different measurement on a different weight. This calculation does not predict it.
The chart also permits 2 lb of nitrite to 100 gallons of pickle at a 10 percent pump level. That figure is not converted here, because converting it requires the density of the pickle, which the regulation does not state.