OFFICE OF CHEMICAL SAFETY
AND POLLUTION PREVENTION
                 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                            WASHINGTON, D.C.  20460
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MEMORANDUM

DATE:		September 10, 2012

SUBJECT:	Toxicology Scoping Document for the Registration Review of Methyl Nonyl Ketone

				Registration Review Case #: 	3094
				PC Code: 					044102				
				CAS #:						112-12-9
				Chemical Class: 				Biochemical

FROM:		Angela L. Gonzales, Biologist 	
            Biochemical Pesticides Branch
            Biopesticides & Pollution Prevention Division (7511P)
            				
TO:			Gina Burnett, Regulatory Action Leader
				Biochemical Pesticides Branch
            Biopesticides & Pollution Prevention Division (7511P)

                                       

ACTION REQUESTED

The following document contains the incident data assessment for the biopesticide methyl nonyl ketone (2-undecanone) in support of the development of the Registration Review Work Plan.  


Executive Summary

In the previous scoping document for registration review of this chemical, the Agency indentified a substantial number of incident reports for methyl nonyl ketone and indicated that the next step in the registration review process would be to determine if the information in the incident reports warranted a reevaluation of the current risk assessments. The Agency has since conducted a review of the available data and information does not foresee the need for new data or for new risk assessments for methyl nonyl ketone. All mammalian health assessment data requirements under 40 CFR 158.2050 have been satisfied. Based on the review of the toxicology database and incident data available to the Agency, there does not appear to be a concern at this time that would warrant further investigation or reevaluation of current risk assessments. There is reasonable certainty of no harm to the general population from exposure to methyl nonyl ketone in pesticide products when they are used according to label instructions. The Agency will continue to monitor incident data and if a concern is triggered, additional analysis will be included in the risk assessments. 
  



I. Background

Methyl nonyl ketone is used as a dog and cat repellent in indoor and outdoor residential settings.  Products are applied on objects and around the borders of areas to be protected from dogs and cats.  The active ingredient is also employed in a pesticide product as an insect repellent which is applied to skin and clothing.  This product is primarily for use as a mosquito and tick repellent. Methyl nonyl ketone is the sole active ingredient in all registered products. 
        
II. Incidents

According to the Incident Data System, there have been 452 reports of incidents occurring between January 1, 1992 and October 27, 2011 from use of products containing methyl nonyl ketone as the active ingredient.  A summary of the classification of these incidents is provided in table 1 below.
  
      Table 1. Incident Data Summary for Methyl Nonyl Ketone (1992-2011)
                            Description of Incident
                               Number of Reports
                         Domestic Animal  -  Fatality
                                      11
                           Domestic Animal  -  Major
                                       7
                         Domestic Animal  -  Moderate
                                      34
                Domestic Animal  -  Moderate, Minor and Unknown
                                      170
                        Domestic Animal  -  Unspecified
                                       9
                                Human  -  Minor
                                      180
                            Human  -  Unspecified 
                                       3
                             Plant Damage - Minor
                                       1

Incidents have been reported from the use of cat and dog repellent products in the form of emulsifiable concentrates, pressurized liquids and granular formulations.  As of the date of the report, no incidents have been reported for the insect repellent product.  

III. Discussion

The Agency has reviewed the available toxicology and incident data to determine if a reevaluation of current risk assessments is necessary. Based on the review of these data and information, there does not appear to be a concern at this time that would warrant further investigation and/or reevaluation of current risk assessments.

Acute toxicology data indicate that methyl nonyl ketone is of low oral and dermal toxicity, it is a mild eye and moderate skin irritant, and is a weak skin sensitizer. Subchronic (repeat-dose) oral toxicity data were not required for the active ingredient based on the use pattern, as repeated oral exposure is not anticipated. There were no systemic effects reported in rabbits at the highest dose tested (300 mg/kg/day) in a 21-day dermal toxicity study. Subchronic inhalation toxicity data were not required based on the low volatility and use pattern of the active ingredient. Available data suggest that methyl nonyl ketone is not mutagenic or a developmental toxicant. 

A discussion regarding the incidents is provided below. The "plant damage-minor" incident is not addressed, as this document is specific to mammalian incidents.

Animal Incidents

There is very little specific information regarding animal incidents available to the Agency. The majority of incidents to animals were classified as moderate, minor or unknown in nature. The information available to the Agency regarding these incidents indicates that they did not likely occur when the chemical was used according to label instructions. The Agency is not in receipt of data that indicate that the pesticide was the direct cause of the incidents. Based on obtainable information, incidents were likely due to other causes, such as existing illness, misuse of product, exposure to other toxic entities, accidental exposure, and ingestion of treated articles (e.g.: trash).

Human incidents

There is very little specific information regarding human incidents available to the Agency. Of the 183 human incidents, 180 were minor in nature; the remaining 3 were unspecified. The information available to the Agency regarding these incidents indicates that they did not likely occur when the chemical was used according to label instructions. The Agency is not in receipt of data that indicate that the pesticide was the direct cause of the incidents. Based on obtainable information, incidents were likely due to other causes such as existing illness, misuse of product, and accidental exposure.  

IV. Conclusion

Based on the known toxicological profile of methyl nonyl ketone as a chemical of low toxicity (with the exception that it is a moderate skin irritant), the low severity of reported incidents, and that details of incidents available to the Agency indicate that incidents were likely due to other causes (misuse, accidental exposure, etc.), there does not appear to be a concern at this time that would warrant further investigation or reevaluation of current risk assessments. There is reasonable certainty of no harm to the general population from exposure to methyl nonyl ketone in pesticide products when they are used according to label instructions. The Agency will continue to monitor incident data and if a concern is triggered, additional analysis will be included in the risk assessments.




cc:  A. L. Gonzales, G. Burnett, BPPD Science Review File, IHAD/ARS
 	  A. L. Gonzales, FT, PY-S: 09/10/12



	 
