Acute illnesses associated with exposure to fipronil--surveillance data from 11 states in the United States, 2001-2007.

Introduction: Fipronil is a broad-spectrum phenylpyrazole insecticide widely used to control residential pests and is also commonly used for flea and tick treatment on pets. It is a relatively new insecticide and few human toxicity data exist on fipronil.

Objective: This paper describes the magnitude and characteristics of acute illnesses associated with fipronil exposure.

Methods: Illness cases associated with exposure to fipronil-containing products from 2001 to 2007 were identified from the Sentinel Event Notification System for Occupational Risks (SENSOR)-Pesticides Program and the California Department of Pesticide Regulation.

Results: A total of 103 cases were identified in 11 states. Annual case counts increased from 5 in 2001 to 30 in 2007. Of the cases, 55% were female, the median age was 37 years, and 11% were <15 years old. The majority (76%) had exposure in a private residence, 37% involved the use of pet-care products, and 26% had work-related exposures. Most cases (89%) had mild, temporary health effects. Neurological symptoms (50%) such as headache, dizziness, and paresthesia were the most common, followed by ocular (44%), gastrointestinal (28%), respiratory (27%), and dermal (21%) symptoms/signs. Exposures usually occurred from inadvertent spray/splash/spill of products or inadequate ventilation of the treated area before re-entry.

Conclusions: Our findings indicate that exposure to fipronil can pose a risk for mild, temporary health effects in various body systems. Precautionary actions should be reinforced to prevent fipronil exposure to product users.