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      UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
       	     WASHINGTON, D.C. 20460
      		
      
      				Office of Chemical Safety and Pollution Prevention 
   				 
   
                                         
   
   MEMORANDUM                                                                 May 22, 2012
   

SUBJECT:	Request for Scoping Document on Sodium Bicarbonate, and Potasium Bicarbonate 

				EPA Reg. #: 
 				Chemical Class: Biochemical
                             PC Code : 073401, 073505, 073508
       				CAS Number: 1066-33-7 ; 144-55-8 ; 298-14-6
                                                                  
FROM:		Miachel Rexrode, Ph.D, Senior Biologist        /S/        05/22/2012
            Biochemical Pesticides Branch
            Biopesticides & Pollution Prevention Division (7511P)

TO:			Leonard Cole, Regulatory Action Leader     /S/          05/22/2012
            Biochemical Pesticides Branch
            Biopesticides & Pollution Prevention Division (7511P) 





ACTION REQUESTED

This is a Scoping Document for Sodium Bicarbonate, and Potasium 
Bicarbonate that evaluates potential risk to non-target and Endangered Species.  






RECOMMENDATIONS AND CONCLUSIONS


Executive Summary
Based on the available data and information, the Agency does not foresee the need for new ecotoxicity data and risk assessments for the bicarbonates; Sodium Bicarbonate, and Potasium Bicarbonate.


Potassium Bicarbonate (Carbonic acid, monopotassium salt) and Sodium Bicarbonate (Carbonic acid, monosodium salt; baking soda)

These two compounds are found throughout nature in living systems and in non-living environments. They are an integral part of humans, other animals, plants, and virtually all living organisms, and are crucial for normal function. They are also present in soils, water, rocks, and other parts of the environment and are found in many consumer products. These compounds are used as biological pesticides on all food commodities, turf, flowers, and ornamentals. The pesticide products that contain these bicarbonates are diluted with water and sprayed on foliage using ground equipment in order to combat fungal diseases.

No adverse human health effects are expected when potassium bicarbonate or sodium bicarbonate are used as pesticides. The compounds are ubiquitous in nature; considered to be "generally recognized as safe" (GRAS) by the Food and Drug Administration; naturally present in human food; widely distributed in commerce; available to the general public for non-pesticidal uses; and required for normal function in human, animal, plant and environmental systems. Potassium bicarbonate and sodium bicarbonate are not associated with adverse effects to humans.


Ecotoxicity 

Table 1.0 shows acute toxicity studies for the Bicarbonates. The values for sodium bicarbonate and potasium bicarbonate suggest that these compounds are practically non-toxic (LC50 > 100 mg/L) to aquatic organisms on an acute basis. 

Table 1.0 Ecotoxicity Data for Sodium Bicarbonate and Potassium Bicarbonate (PAN Data Base)
Chemical
Test Organism
Test Results
Sodium Bicarbonate
Sheepshead Minnow (Cyprinodon variegatus) 
LC50 = 3,293 mg/L

Mosquito (Culex sp.)
LC50 = 2,000 mg/L

Diatom (Nitzschia linearis)
LC50 = 650 mg/L

Daphnia (Daphnia magna)
EC50 = 1,554 mg/L

Rat (Rattus norvegicus)
LD50 = 4,220 mg/kg
Potassium Bicarbonate
Fathead Minnow (Pimephales promelas)
LC50 = 260 mg/L

Daphnia (Daphnia magna)
EC50 = 93 - 450 mg/L



Risk Assessment

Potassium and Sodium Bicarbonate are biochemical pesticides that are exempt from the requirement of a tolerance in or on all raw agricultural commodities when applied as a fungicide (§180.117 and §180.1176). These two compounds are found in all living and non living environmental systems and are also present in soils, water, rocks, as well as, consumer products. Potassium Bicarbonate and Sodium Bicarbonate are not associated with adverse effects to the environment and are expected to show No Effect (NE) to endangered/threatened species. These compounds display a non-toxic mode of action, occur naturally, have a history of exposure to humans and the environment with minimal toxicity, are typically applied at low use rates that do not exceed background levels, degrade rapidly in the environment, and are typically indistinguishable from identical substances already present in the environment.




