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CFSAN/Office of Food Additive Safety
September 5, 2006
Date: September 5, 2006
From: Environmental Toxicologist, Environmental Review Group (ERG)
Division of Chemistry Research and Environmental Review (HFS-246)
Subject: FCN No. 645 - Chlorine dioxide as an antimicrobial agent in water used in poultry processing and to wash fruits and vegetables.
Notifier: Selective Micro Technologies
c/o Keller and Heckman, LLP
Washington, D.C., USA
To: Division of Food Contact Notifications (HFS-275)
Attention: Vivian Gilliam
Through: Layla I. Batarseh, Ph.D., Supervisor, ERG
Attached are the Finding of No Significant Impact (FONSI) and our supplement to the notifier's environmental assessment (EA) for FCN 645. When this notification becomes effective, these documents and the notifier's revised EA (in PDF*, 629Kb), dated August 18, 2006, may be made available to the public, and we will post them on the internet at http://www.cfsan.fda.gov/~rdb/opa-envt.html.
Please let us know if there is any change in the identity or use of the food-contact substance.
2 Attachments:
Finding of No Significant Impact
Supplement to the Environmental Record for Food Contact Notification No. 645
A food contact notification (FCN No. 645), submitted by Selective Micro Technologies, to provide for the safe use of chlorine dioxide as an antimicrobial agent in water used in poultry processing and to wash fruits and vegetables.
The Environmental Review Group 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 the notification, including a revised environmental assessment (in PDF*, 629Kb), dated August 18, 2006, and our supplement to the environmental record.
Prepared by__________________________________________Date: September 5, 2006
Katrina E. White, Ph.D., Environmental Toxicologist
Environmental Review Group
Division of Chemistry Research and Environmental Review
Office of Food Additive Safety
Center for Food Safety and Applied Nutrition
Food and Drug Administration
Approved by__________________________________________Date: September 5, 2006
Layla I. Batarseh, Ph.D., Supervisor
Environmental Review Group
Division of Chemistry Research and Environmental Review
Office of Food Additive Safety
Center for Food Safety and Applied Nutrition
Food and Drug Administration
This document incorporates by reference the notifier's revised environmental assessment (EA) (in PDF*, 629Kb) dated August 18, 2006.
The purpose of this supplement is to ensure the accuracy and completion of the environmental record and to assist the public in understanding the agency's basis for preparing a finding of no significant impact (FONSI).
Item 5. Identification of Chemical Substances that are the Subject of the Proposed Action.
The EA states, "Because no ionic compounds can diffuse across the membrane into solution, the resultant chlorine dioxide solution is nearly pure (greater than 99% of the total oxychloro species)." The environmental review group (ERG) notes that chlorine dioxide is unstable and will rapidly form chlorite, chloride, chlorate, and other disinfection by-products,1 which we expect to be present at the time of generation of ClO2 (1,2).
Item 6. Introduction of Substances into the Environment.
6.c. Wastewater Treatment of Discharged Process Water.
The EA assumed that the average poultry or fruit and vegetable processing facility are expected to contribute 13.5% of the influent to a publicly owned treatment works (POTW). This assumption was based on a survey of 30 POTWs that experienced operational interferences and was referenced in food additive petitions 4A4408 and 4A4415.2 The survey found that industrial users accounted for approximately 27% of POTW use and the EAs assumed that an individual industry was assumed to make up half of the 27%, to arrive at 13.5%. ERG knows that the contribution of industrial flow to total flow at POTWs is highly variable and in some cases a single industrial discharger may contribute to a large percentage of municipal effluent. For example, in a detailed survey of meat processing facilities, nine meat-processing facilities had a flow equal to or larger than their corresponding municipalities (3). Although, 13.5% is a reasonable estimate of the contribution of industrial flow to municipal flow, ERG does not consider it a conservative dilution factor of the contribution of industrial flow to POTW flow. When wastewater will not always be discharged to a POTW, dilution in a POTW should not be considered in a conservative estimate of the predicted environmental concentrations. ERG knows that some food processing facilities discharge water directly to surface water. For example, in a survey of 39 poultry processors, published in 2001, 57% percent discharged wastewater directly to surface waters (4). Therefore, ERG calculated conservative expected environmental concentrations (EECs) without considering dilution in a POTW.
Conservative Expected Environmental Concentrations.
ERG calculated conservative EECs based on the following assumptions (Table 1).
| Type of Use | Compound | EEC (mg/L) | Lowest Toxicity Endpoint (mg/L) |
|---|---|---|---|
| Poultry Processing | Chlorite | 0.0084 | 0.027 |
| Chlorate | 0.18 | 133 | |
| Fruit and Vegetable Processing | Chlorite | 0.0035 | 0.075 |
| Chlorate | 0.027 | 133 |
The basis of the FONSI in regards to aquatic toxicity is that the conservative calculated EECs are all below the lowest measured toxicity endpoints for chlorites and chlorates. Additionally, chloride concentrations in wastewater are expected to be well below the freshwater Criterion Continuous Concentration (CCC)5 of 230 mg/L for chloride (9).
Item 7. Fate of Emitted Substances in the Environment.
Wastewater Treatment. The EA, under Section 7.a., assumes that 100% of the chlorite load will be reduced to chloride. ERG agrees that most of the chlorite, greater than 99%, will be reduced to chloride (1). However, a very small percentage is expected to survive the wastewater treatment process.
Discharge as Irrigation Water. The EA, under Section 7.b., states, "Groundwater protection regulations do not permit a processor to apply more nutrients to irrigated crop than they are capable of using during the growing season." ERG agrees that almost all states have statutes that apply to nonpoint source discharge that were established to prevent contamination of ground water and surface waters (10). However, management practices vary from state to state and regulations preventing the discharge of excess nutrients to crop lands do not exist in every state (11). The primary concern for use of wastewater treated with the FCS for irrigation purposes is the presence of salts, including chloride. Salts in irrigation water may contribute to 1) the build up of excess salts in soil which can reduce plant growth or seed germination, 2) alteration of soil structure and absorption properties, and 3) movement of excess salts to ground water or surface water (12). The effect of wastewater used for irrigation purposes is dependent on management practices and site specific factors (12). When best management practices developed by the United States Environmental Protection Agency (EPA) are followed, ERG believes that land application of wastewater will reduce use of water by recycling water for irrigation and reduce the cost of treatment of wastewater.6 Additionally, the chloride concentrations in wastewater used for irrigation purposes is not expected to cause a reduction in crop yield (13).
Literature Cited
Prepared by__________________________________________Date: September 5, 2006
Katrina E. White, Ph.D., Environmental Toxicologist
Environmental Review Group
Division of Chemistry Research and Environmental Review
1 Chlorine dioxide does not form trihalomethanes as disinfection by-products but it can result in other lower chlorinated organics (1).
2 See page 6 and 7 of the amended EA submitted for Food Additive Petition 4A4415, dated October 3, 1996, and page 3 of the FONSI of food additive petition 4A4408.
3 The remaining 14% or reaction products produced from chlorine dioxide were assumed to be minor.
4 ERG has examined dilution factors (DF) at poultry first processing plants and found that 71% of facilities had DFs greater than 100 and 96 percent had a DF of 20 or greater (8). A DF of 10 for all food processing facilities is assumed to be a conservative DF for the majority of food processing facilities.
5 The CCC is an estimate of the highest concentration of a material in surface water to which an aquatic community can be exposed indefinitely without resulting in an unacceptable effect.
6 Information on EPA's best management practices is available at: http://www.epa.gov/ebtpages/envibestmanagementpractices.html.
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