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CFSAN/Office of Food Additive Safety
May 22, 2001
Date: May 22, 2001
From: Chemistry and Environmental Review Team (CERT)
Division of Product Policy (HFS-207)
Subject: FCN No.140 - A mixture of peroxyacetic acid, acetic acid, hydrogen peroxide, and 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) as an antimicrobial agent for red meat carcasses
Notifier: Ecolab, Inc.
370 Wabasha Street
St. Paul, MN 55102
To: Division of Petition Control (HFS-215)
Attention: Parvin Yasaei, Ph.D.
Through: Team Leader, CERT
Attached is the Finding of No Significant Impact (FONSI) for this premarket notification. When the notification becomes effective, this FONSI, the notifier's Environmental Assessment, dated March 13, 2001, and the Supplement to the Environmental Assessment prepared by CERT and dated May 21, 2001, may be made available to the public.
Please let us know if there is any change in the identity or use of the food-contact substance that would be inconsistent with the identity and use described in the FONSI
Paul C. DeLeo, Ph.D.
Environmental Scientist
A premarket notification (FCN No. 140), submitted by Ecolab, Inc., to provide for the safe use of a mixture of peroxyacetic acid, acetic acid, hydrogen peroxide, and 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) as an antimicrobial agent on red meat carcasses.
The Chemistry and Environmental Review Team has determined that allowing this notification to become effective will not significantly affect the quality of the human environment and therefore will not require the preparation of an environmental impact statement. This finding is based on information submitted by the notifier in an Environmental Assessment dated March 13, 2001, and on the analysis in a supplement to the Environmental Assessment prepared by a scientist on the Chemistry and Environmental Review Team, and dated May 21, 2001.
Prepared by: _____________________________________________ Date: May 22, 2001
Paul C. DeLeo, Ph.D., Environmental Scientist
Chemistry and Environmental Review Team
Division of Product Policy
Office of Premarket Approval
Center of Food Safety and Applied Nutrition
Food and Drug Administration
Approved by: _____________________________________________ Date: May 22, 2001
Layla I. Batarseh, Ph.D., Team Leader
Chemistry and Environmental Review Team
Division of Product Policy
Office of Premarket Approval
Center of Food Safety and Applied Nutrition
Food and Drug Administration
May 21, 2001
This document incorporates by reference the notifier's Environmental Assessment (EA) dated March 13, 2001.
This supplement to the EA for FCN 140 provides additional discussion related to the environmental fate and effects of constituents in the notifier's antimicrobial solution KX 6091. Specifically, the environmental fate of 1 hydroxyethylidene-1,1-diphosphonic acid (HEDP) is discussed with respect to potential eutrophication of fresh water bodies. Discussion of the ecotoxicity of HEDP and acetic acid also is provided.
Eutrophication Potential from HEDP
Under Format Item 7, the notifier did not discuss the environmental fate of HEDP. We prepared the following analysis of the environmental fate of HEDP with a focus on potential phosphorus loading to aquatic environments leading to increased eutrophication.
HEDP is used as a stabilizer in peroxide solutions, a chelating agent (especially effective in chelating calcium ions), and as a dispersant in cleaning formulations. U.S. consumption of HEDP in 1994 was approximately 30 million pounds with an annualized growth rate for the previous five years of 4.2% that was expected to continue in the future.
The environmental fate of HEDP was predicted using the EPIWIN (ver. 2.2) Quantitative Structure Activity Relationship (QSAR) computer model. The results from EPIWIN were compared to empirical data reported in the scientific literature. EPIWIN predicted a high boiling temperature (457°C), a very high aqueous solubility (6.5 H 105 mg/L), a very low vapor pressure (1.7 H 10-7 mm Hg to 3 H 10-12 mm Hg), a very low Henry's Law Constant (9.8 H 10-26 atm-m3/mole), and a volatilization rate in water that was nearly zero (t1/2 > 1018 years). Empirical data
EPIWIN predicted that HEDP "does not biodegrade fast" using both linear and non-linear models; the expert rating for primary biodegradation was predicted as days-weeks. Laboratory research on HEDP confirms that it does not readily biodegrade aerobically; anaerobic biodegradation also is very slow, if it occurs at all. In natural systems, photodegradation yielding acetate and inorganic phosphate has been observed as an abiotic degradation mechanism.
EPIWIN predicted a low soil adsorption coefficient (Koc) of 20.8 (log Koc = 1.3) and low removal of HEDP (1.85%) during wastewater treatment with the primary mechanism being sludge adsorption. This means that most of the compound was predicted to remain with the wastewater through treatment and to be discharged to the environment. However, researchers have determined that adsorption has a much greater effect on the removal of HEDP from liquid waste streams than that predicted by EPIWIN. In fact, the primary mechanism observed in the removal of HEDP from liquid waste streams is adsorption. This contradiction is not unusual as the Koc approach to predicting chemical sorption (and mobility) tends to provide conservative results; that is, lower adsorption coefficients (and higher mobility) are generally predicted than are observed in experimental or natural systems. Freundlich adsorption constants (kd; kd = Koc * % organic carbon/100) of 1,000 to 2,000 have been measured for HEDP in sediment-water systems, and higher adsorption constants have been measured for sewage sludge systems; this is partly due to the high organic matter content of sewage sludge. Contrary to the prediction of EPIWIN, high levels of removal of HEDP and other phosphonates (50-80%) have been observed during wastewater treatment as the result of adsorption to the sewage sludge.
Degradation of phosphonate sorbed to sewage sludge is not likely to occur; therefore, the ultimate fate of phosphonate in sludge depends on the ultimate disposal of the sludge. If the sludge is incinerated or (wet-air) oxidized, the phosphonate will be transformed to the basic oxidized compounds (CO2 and PO43+); the phosphate formed will likely become part of an insoluble metal ion complexes in the ash or oxidized sludge that will be immobile. If the sludge is land applied, the phosphonate will likely degrade to CO2 and PO43+ over the longer term with the phosphate forming insoluble complexes in the amended soil.
The degradation of HEDP discharged to aquatic environments will not occur rapidly. However, we have no concerns about the fate of HEDP and potential impacts on eutrophication of fresh water bodies resulting from the requested use because the quantity of phosphorus from HEDP in the liquid waste stream of beef processing facilities using the subject antimicrobial solution will be a very small fraction of the total phosphorus load. Waste from a beef processing facility also is typically treated prior to discharge to the environment, and these treatment systems are designed to deal with high levels of phosphorus. That is because the liquid waste stream at beef processing facilities (slaughterhouses), which is often characterized as "high strength," ordinarily has BOD greater than 1,000 mg/L, nitrogen (total Kjeldahl nitrogen) greater than 100 mg/L and total phosphorus of 10-50 mg/L. In the EA, the notifier estimated the concentration of HEDP in the liquid waste stream; the concentration of phosphorus from HEDP would be roughly three orders of magnitude less than the concentration of phosphorus resulting from the other meat processing activities.
Johns provided a detailed discussion of wastewater treatment in the meat processing industry. The simplest treatment of beef processing wastewater would involve primary treatment using settling ponds with dissolved air flotation; these systems usually have long retention times. A more common treatment for beef processing wastewater in the U.S. is conventional activated sludge; most of these systems have extended aeration designs to reduce the high BOD load and minimize sludge production. Other aerobic wastewater pond systems are also common. Anaerobic wastewater treatment systems have become more widely used recently because they can achieve a high degree of BOD removal at lower cost, and previous technical complications have been solved; anaerobic systems typically have long retention times (several days) and high biomass concentrations. In addition to conventional systems designed to treat high BOD loads, some systems also include chemical treatment for nutrient (nitrogen and phosphorus) removal or biological nutrient removal systems. For wastewater treatment systems that are designed to address the high BOD load, the long retention times and high biomass concentrations will lead to substantial removal of HEDP from the wastewater via adsorption to the sludge. For wastewater treatment systems with biological nutrient removal, additional phosphorus removal will be achieved resulting in reduced releases to waters receiving treated waste from a given beef processing facility.
Ecotoxicity of HEDP and Acetic Acid
Under Format Item 8, the notifier discussed the environmental toxicity of HEDP. We agree with the conclusion that HEDP is practically non toxic to many aquatic and avian organism; however, the Material Safety Data Sheet (MSDS) for HEDP provided with the EA indicated that some organisms were sensitive. The most sensitive organism was algae; the LC50 of HEDP for algae was 10-100 mg/L due to the nutrient chelating ability of phosphonates. In addition, the notifier stated that HEDP is slightly toxic to oysters (EC50 of 10-100 mg/L). Using the application rate provided by the notifier, we estimated a conservative concentration of 20 5g/L of HEDP in the effluent discharged from a typical wastewater treatment plant receiving the liquid waste from a processing plant using the subject antimicrobial solution; this assumes no degradation, dilution, or adsorption. This conservative estimate is a factor of 500 less than the lowest concentration toxic to oysters and algae (10 mg/L). We have no concerns about the environmental toxicity of HEDP resulting from the requested use.
In addition, the notifier discussed the environmental toxicity of acetic acid. The notifier stated that the reported 96-hour fish LC50s are in the range of 80 mg/L. This information is accurate. However, we believe that, because of the rapid breakdown of acetic acid in the aquatic environment, a more appropriate toxicity endpoint for acetic acid would be the acute 24-hour median toxic level of 47 mg/L for Daphnia magna. We have no concerns about the environmental toxicity of acetic acid resulting from the requested use since the notifier's estimate of the expected introduction concentration of acetic acid to the aquatic environment following wastewater treatment was roughly a factor of 300 less than the environmental toxicity endpoint of concern.
