Bed bugs are the scourge of most major North American cities and the cost of having a professional service rid them can be cost prohibitive to some. In many of these cases people resort to a Do It Yourself (DIY) approach. Professionals time and again reiterate the importance of reading a pesticide label and following the directions (and safety precautions) precisely. And here is why …
Evaluation of Pesticide Incident Report 2010-1615
Background
Health Canada’s Pest Management Regulatory Agency (PMRA) collects incident reporting data under the authority of the Pest Control Products Act. If a pesticide manufacturer receives information about an incident involving one of their products, they are required by law to submit that information to the PMRA. All submitted incident reports are made publicly available on the Health Canada website, specifically, on the PMRA 
Public Registry. It is important to note that the information presented in incident reports reflects the observations and opinion of the person reporting it, and does not include any assessment by Health Canada, nor does it confirm an association between the pesticide and the effects reported.
Health Canada considers the reported information to determine if there are potential health or environmental risks associated with a pesticide and, if necessary, takes corrective action. Such action could range from minor label changes to discontinuation of the product.
Incident Report 2010-1615
Wellmark International received information about an incident related to one of their products, which they submitted to the PMRA on April 29, 2010. The information contained in the incident report indicated that a product containing the active ingredients permethrin and S-methoprene was sprayed between the mattresses and on the perimeter of the floor in a person’s bedroom. The individual slept on the bed the night the product was sprayed and was hospitalized approximately two days later with symptoms including vomiting, chemical taste in the mouth, pneumonia, paralysis, and scarring of the lung tissue. The individual passed away after 18 days of hospitalization. The report indicated that the individual had a history of diabetes and chronic obstructive pulmonary disease. In accordance with the Incident Reporting Regulations classification system, this incident was classified as Human Death. It was also reported that the individual’s daughter, who applied the product, experienced bronchitis, which is considered to be moderate in severity.
As required by the Pest Control Products Incident Reporting Regulations, Wellmark International submitted the incident report to the PMRA and it is posted on the PMRA electronic Public Registry on the Health Canada website.
Health Canada Evaluation
The person who reported this information to Wellmark International was not certain as to the specific product used in this incident. However, it is likely that the product used was one of three domestic-class products registered by Wellmark International for use in Canada: Vet-Kem Siphotrol Forte (PCP Reg. No. 22213), Vet-Kem Siphotrol 1000 Double Action Premise Treatment (PCP Reg. No. 25739) and Vet-Kem Siphotrol 2000 Double Action Premise Treatment (PCP Reg. No. 25582) all containing permethrin and S-methoprene at low concentrations (0.01-0.80%).
Permethrin belongs to the class of insecticides known as pyrethroids. Symptoms of overexposure to pyrethroids in general may include vomiting and irritation of the respiratory tract. S-methoprene is an insect growth regulator that mimics a natural hormone of insects and prevents the maturation and reproduction of young insect pests. S-methoprene has relatively low toxicity and is not associated with adverse reactions in humans.
In this incident, there was no physical evidence, such as laboratory results, available to confirm that exposure to permethrin or S-methoprene had occurred. There may be several other causes of the reported effects that cannot be ruled out. A review of Canadian and U.S. incident reporting information indicated that there is no clear trend for any of the symptoms reported. None of the symptoms reported are expected to result from exposure to S-methoprene. The symptoms of vomiting and chemical taste in the mouth that the individual experienced, as well as the bronchitis experienced by the individual’s daughter, are not inconsistent with the known symptoms of over-exposure to permethrin. However, the more serious symptoms of paralysis, pneumonia and scarring of the lung tissue as well as death are not expected to result from short-term exposure to permethrin.
Health Canada Conclusion
Based on the available information, it is concluded that it is unlikely (where the effect reported is not typical for the suspected pesticide but the possibility that exposure to the pesticide caused the effect cannot be ruled out) that the symptoms of paralysis, pneumonia and scarring of lung tissue, as well as the reported death, are related to exposure to the pesticide product. The health of the individual may have been compromised from other medical issues at the time that the incident occurred; therefore, it is uncertain if the subject’s medical conditions may have been exacerbated by exposure to the pesticide.
It is possible (where there is some correlation between the exposure, the pesticide and the effect) that the vomiting and chemical taste in the mouth reported in the individual that died, and the bronchitis reported in the individual that sprayed the product, were related to exposure to permethrin.
It should be noted that it is not clear what specific product was used in this case. It is also important to note that this incident involved application to a mattress, which is not an approved use for either permethrin or S-methoprene.
The information as noted in the incident will remain in the database and will be routinely re-examined in conjunction with any new data that is received. It is important to note that a product is only registered for use if there is reasonable certainty that no harm will result from exposure to or use of the product as directed on the label.
More information about the Incident Reporting Program is available on Health Canada’s website. Should you require further information please contact the Pesticide Incident Reporting Program.
Tags: Canada, death, permethrin
