THE SECRETARY MAY DEVELOP EMERGENCY PROCEDURES FOR DESIGNATING AGRICULTURAL PRODUCTS THAT ARE COMMERCIALLY UNAVAILABLE IN ORGANIC FORM FOR PLACEMENT ON THE NATIONAL LIST FOR A PERIOD OF TIME NOT TO EXCEED 12 MONTHS.

7 CFR § 205.600(b)

(b) In addition to the criteria set forth in the Act, any synthetic substance used as a processing aid or adjuvant will be evaluated against the following criteria:
(1) The substance cannot be produced from a natural source and there are no organic substitutes;
(2) The substance's manufacture, use, and disposal do not have adverse effects on the environment and are done in a manner compatible with organic handling;
(3) The nutritional quality of the food is maintained when the substance is used, and the substance, itself, or its breakdown products do not have an adverse effect on human health as defined by applicable Federal regulations;
(4) The substance's primary use is not as a preservative or to recreate or improve flavors, colors, textures, or nutritive value lost during processing, except where the replacement of nutrients is required by law;
(5) The substance is listed as generally recognized as safe (GRAS) by Food and Drug Administration (FDA) when used in accordance with FDA's good manufacturing practices (GMP) and contains no residues of heavy metals or other contaminants in excess of tolerances set by FDA; and
(6) The substance is essential for the handling of organically produced agricultural products.

7 CFR § 205.605(b)

(b) Synthetics allowed:
Alginates.
Ammonium bicarbonate--for use only as a leavening agent.
Ammonium carbonate--for use only as a leavening agent.
Ascorbic acid.
Calcium citrate.
Calcium hydroxide.
Calcium phosphates (monobasic, dibasic, and tribasic).
Carbon dioxide.
Cellulose--for use in regenerative casings, as an anti-caking agent (non-chlorine bleached) and filtering aid.
Chlorine materials--disinfecting and sanitizing food contact surfaces, Except, That, residual chlorine levels in the water shall not exceed the maximum residual disinfectant limit under the Safe Drinking Water Act (Calcium hypochlorite; Chlorine dioxide; and Sodium hypochlorite).
Ethylene--allowed for postharvest ripening of tropical fruit and degreening of citrus.
Ferrous sulfate--for iron enrichment or fortification of foods when required by regulation or recommended (independent organization).
Glycerides (mono and di)--for use only in drum drying of food.
Glycerin--produced by hydrolysis of fats and oils.
Hydrogen peroxide.
Lecithin--bleached.
Magnesium carbonate--for use only in agricultural products labeled "made with organic (specified ingredients or food group(s))," prohibited in agricultural products labeled "organic".
Magnesium chloride--derived from sea water.
Magnesium stearate--for use only in agricultural products labeled "made with organic (specified ingredients or food group(s))," prohibited in agricultural products labeled "organic".
Nutrient vitamins and minerals, in accordance with 21 CFR 104.20, Nutritional Quality Guidelines For Foods.
Ozone.
Pectin (low-methoxy).
Phosphoric acid--cleaning of food-contact surfaces and equipment only.
Potassium acid tartrate.
Potassium tartrate made from tartaric acid.
Potassium carbonate.
Potassium citrate.
Potassium hydroxide--prohibited for use in lye peeling of fruits and vegetables except when used for peeling peaches during the Individually Quick Frozen (IQF) production process.
Potassium iodide--for use only in agricultural products labeled "made with organic (specified ingredients or food group(s))," prohibited in agricultural products labeled "organic".
Potassium phosphate--for use only in agricultural products labeled "made with organic (specific ingredients or food group(s))," prohibited in agricultural products labeled "organic".
Silicon dioxide.
Sodium citrate.
Sodium hydroxide--prohibited for use in lye peeling of fruits and vegetables.
Sodium phosphates--for use only in dairy foods.
Sulfur dioxide--for use only in wine labeled "made with organic grapes," Provided, That, total sulfite concentration does not exceed 100 ppm.
Tartaric acid.
Tocopherols--derived from vegetable oil when rosemary extracts are not a suitable alternative.
Xanthan gum.