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1-methylcyclopropene (1-MCP) NYSDEC Letter - Major Change in Labeling 9/02

New York State Department of Environmental Conservation
Division of Solid & Hazardous Materials
Bureau of Pesticides Management
Pesticide Product Registration Section
625 Broadway, Albany, New York 12233-7257
Phone: 518-402-8768 FAX: 518-402-9024

September 5, 2002


Ms. Stephanie Hacker
Kelly Registration Systems Service Center
10115 Highway 142 N
Covington, Georgia 30014

Dear Ms. Hacker:

Re: Registration of the Pesticide Product SmartFresh (EPA Reg. No. 71297-2), Which Represents a Major Change in Labeling for the Active Ingredient 1-Methylcyclopropene (1-MCP)

The New York State Department of Environmental Conservation (the Department) has reviewed the application, received July 30, 2002, to register the above-mentioned product in New York State. The application was submitted by the Kelly Registration Systems Service Center on behalf of AgroFresh, Inc. a subsidiary of the Rohm and Haas Company. The SmartFresh product represents a major change in labeling for the active ingredient 1-methylcyclopropene (1-MCP) (chemical code 224459).

The Department originally reviewed and registered 1-MCP as a new active ingredient on December 8, 1999. The product, EthylBloc, was labeled to extend the life and usefulness of cut flowers, potted flowers, and bedding, nursery or foliage plants.

SmartFresh (EPA Reg. No. 71297-2) is a powder that, when mixed with water in a proprietary generating system, releases the volatile active ingredient 1-MCP. SmartFresh is a postharvest tool for counteracting many of the undesirable effects of both internal (produced within the fruit) and external sources of ethylene on harvested fruit. SmartFresh, by counteracting ethylene, provides many benefits to the fruit during transport and storage.

Harvested fruits must be exposed to the volatile active ingredient of SmartFresh in enclosed areas, such as storage rooms, greenhouses, coolers, shipping containers, enclosed truck trailers, or ambient temperature, refrigerated, or controlled atmosphere food storage facilities. This product is not intended for use outdoors or in other non-enclosed areas.

The United States Environmental Protection Agency (USEPA) stamped "ACCEPTED" label for SmartFresh dated July 17, 2002 contains directions for apples, melons, tomatoes, pears, avocados, mangos, papayas, kiwi fruit, peaches, nectarines, plums, apricots and persimmons. The final product label submitted for registration in New York State contains use directions for apples only.

The Department has reviewed the information supplied to date in support of SmartFresh (EPA Reg. No. 71297-2) which represents a major change in labeling for the active ingredient 1-MCP.


The New York State Department of Health (DOH) stated that limited toxicity testing was required for federal registration of SmartFresh. The SmartFresh product was not very toxic to laboratory animals following oral and dermal exposure, not very irritating to animal skin or eyes (tested on rabbits) nor a skin sensitizer (tested on guinea pigs). Because the active ingredient 1-MCP is released as a gas when the formulated product is moistened, acute, subchronic, developmental toxicity and genotoxicity studies were conducted on 1-MCP by the inhalation route of exposure (in vitro genotoxicity studies involved exposure to 1-MCP in the atmosphere above the culture media).

In an acute inhalation toxicity study, 1-MCP at air concentrations of 1,126 parts per million (ppm), did not cause any clinical toxicity, deaths or pathological findings at necropsy. In a 90-day inhalation toxicity study in rats, the chemical caused some spleen and kidney histopathology at an air concentration of 107 ppm, equivalent to a dose of about 39 milligrams per kilogram body weight per day (mg/kg/day); the no-observed-effect level (NOEL) was 24 ppm, equivalent to 9 mg/kg/day. 1-MCP did not cause any developmental effects in the offspring of pregnant rats exposed via inhalation to this active ingredient during organogenesis at the highest dose tested, 1,029 ppm (equivalent to 543 mg/kg/day). However, maternal toxicity characterized by darkened and/or enlarged spleens occurred at a concentration of 329 ppm (equivalent to 173 mg/kg/day), the NOEL was 107 ppm (equivalent to 56 mg/kg/day). The active ingredient was negative in several genotoxicity assays. A search of the toxicological literature did not find any additional information on 1-MCP.

Based on the toxicology data submitted by the registrant for federal registration, the USEPA established an exemption from tolerance requirements for residues of 1-MCP in or on all food commodities. The USEPA noted that "there is reasonable certainty no harm will result from aggregate exposure of residues of 1-MCP to the U.S. population, including infants and children, when the proposed product is used in accordance with label instructions and good agricultural practices." The USEPA also conducted a dietary risk assessment for several population subgroups including adults, infants and children ages one through six years old. Estimated acute dietary exposures to 1-MCP at the 99th percentile gave respective margins of exposure (MOE) of approximately 79,000, 49,000 and 50,000. These estimates assumed a conservative residue level of 0.01 ppm in apples and several other crops, that 100 percent of all the commodities were treated with 1-MCP, and no loss of 1-MCP occurred from storage, processing or handling. Data submitted in the package indicates that actual residues averaged 0.004 ppm in apples directly after treatment with 1-MCP. The NOEL used for estimating these acute MOEs was 56 mg/kg/day from the rat inhalation developmental toxicity study. In addition, using these assumptions and a NOEL of 9 mg/kg/day from the 90-day rat inhalation study, the USEPA estimated MOEs from chronic dietary exposures to 1-MCP at the 99th percentile for adults, infants and children ages one through six years old of 500,000, 102,000 and 111,000, respectively. These relatively high MOEs are considered adequate to protect consumers in each age group against both short and long-term dietary exposures to 1-MCP.

The USEPA reported the results of a risk assessment for inhalation exposure of workers to 1-MCP. The estimated MOE for a 15-minute exposure to 1,000 ppm (as might result from unprotected early entry into a treatment chamber) was about 5,700. The MOE for a four-hour exposure to a concentration of 50 ppm (as might occur from working in a treatment chamber that was incompletely ventilated) was estimated to be about 1,100. The NOELs used to estimate the 15-minute and the 4-hour exposures to 1-MCP were 56 mg/kg/day (rat inhalation developmental toxicity study) and 9 mg/kg/day (rat 90-day inhalation study), respectively. Generally, the USEPA considers MOEs of 100-fold or greater to provide adequate worker protection.

There are no chemical specific federal or State drinking water standards for 1-MCP. Based on its chemical structure, 1-MCP falls under the 50 microgram per liter New York State drinking water standard for "unspecified organic contaminants" (10 NYCRR Part 5 - Public Water Systems).

Neither SmartFresh nor its active ingredient 1-MCP was very toxic following acute exposures, although subchronic (90-day) inhalation exposure to 1-MCP did cause some histopathological changes in the spleen and kidneys in rats and was associated with similar effects on the spleen in an inhalation developmental toxicity study. Estimates of dietary and worker risks, however, indicate that MOEs are adequate, even using conservative assumptions and when evaluating workers performing tasks in violation of the label (i.e., entering a treatment chamber prior to its ventilation without the use of an appropriate respirator).

The SmartFresh label generally contains adequate precautionary statements to limit worker risks, however, the DOH did have some comments regarding its content. First, the label only requires the use of a "respirator" (in addition to clothing items) if the treatment area is entered prior to being ventilated, without specifying the appropriate respirator type. A simple dust-filtering type respirator will not provide adequate protection from 1-MCP gas. A more appropriate requirement would be a respirator with either an organic vapor-removing cartridge with a pre-filter approved for pesticides or a canister approved for pesticides. This is the type of respirator required on the label of the pesticide product EthylBloc, which also contains 1-MCP. Second, the label repeatedly refers to "fruit" and does not specifically state that the SmartFresh product is only for use on apples (even though it contains use directions only for apples). Because of this terminology, there may be some confusion about which fruit can be treated with SmartFresh.

The Department agrees that the label should be clarified as to the appropriate respirator and for use on apples only. However, due to the use pattern of the product and the cost associated with its use, the product will only be used by experienced apple growers and the possibility of misuse is low. Department staff have discussed the above-mentioned label concerns with the registrant. AgroFresh, Inc. has agreed to clarify the label at the next printing. The updated label must be received by the Department by May 1, 2003.

The Department concludes that SmartFresh should not have an adverse effect on the health of workers or the general public when used as labeled.

The Department has received numerous letters which expressed support of the product and the critical need for this season's use of SmartFresh on harvested apples. New York State apple growers would be at a competitive disadvantage in the market place if SmartFresh was available to apple growers in competing states and not available in New York State. Apples are grown on approximately 57,000 acres and are a major crop in New York State. New York is ranked second, behind Washington State, in the nationwide production of apples.

Therefore, the Department hereby accepts for general use registration in New York State SmartFresh (EPA Reg. No. 71297-2) which represents a major change in labeling for the active ingredient 1-methylcyclopropene (1-MCP).

The continued registration of SmartFresh in New York State will depend upon the receipt of an updated label, which contains all of the above-mentioned clarifications, by May 1, 2003.

Enclosed is your Certificate of Registration and New York State stamped "ACCEPTED" label.

AgroFresh, Inc. is reminded that if New York State registration is requested for this product or for any other product which contains 1-MCP with an increased application rate and/or expanded use sites, the product will be considered a Major Change in Labeling and the Department will require an extensive review.

If you have any questions, please contact Mr. Samuel Jackling, Chief of our Pesticide Product Registration Section, at (518) 402-8768.


Maureen P. Serafini
Bureau of Pesticides Management

cc: w/enc. - N. Kim/D. Luttinger - NYS Dept. of Health
R. Zimmerman/ R. Mungari - NYS Dept. of Ag. & Markets
G. Good/W. Smith - Cornell University, PMEP