Winnipeg can use old malathion pending tests: Health Canada

Winnipegcan use its years-oldmalathion to kill nuisancemosquitoes if laboratory tests show the impuritycontent of the insecticidefalls within acceptable standards, a City of Winnipeg spokesperson says.

Health Canada'sPest Management Regulatory Agency (PMRA) told the citythey will not object to use of malathion more than a year oldif theisomalathion content of the malathionmeetsspecifications such as those laid out by the World Health Organization.

The city is in the process of having its current stock of malathion tested for isomalathion content.

Earlier on Friday,Manitoba Healthsaid itobtained permission from Health Canadato use the pesticide to control West Nile viruseven though most existing stockpiles have been stored formore than one year.

CBC's I-Team informed the City of Winnipeg it is now illegal to store malathion for more than one year. Unbeknownst to the city's insectcontrol branch, federal pesticide regulators changed the product label.

• Health Canada tells Winnipeg it can't fog with years-old malathion

This effectively sidelined malathion as a pesticide, given thatmunicipal stockpiles were purchased in 2007 and 2009and provincial supplies date back to 2008. Provincial officials then contacted Ottawa for clarification.

On Friday, provincial officials said Ottawa has agreed to allow malathion fogging if West Nile presents a public-health risk. But first, the province must send samples of its stockpile to a laboratory in Ontario to ensure the pesticide has not degraded into a more harmful form.

"The Pest Management Regulatory Agency has advised Manitoba Health, Seniors and Active Living that the province's stockpile of malathion (which has been in storage for more than one year) can be used in the case of a public health emergency, providing test results show isomalathion levels are within accepted standards," a spokeswoman for Manitoba Health said in a statement.

Pending test results, theCity of Winnipeg can now possibly use its stockpiles of malathion to kill mosquito speciessuch as Aedesvexans, which are not known totransmitdiseases to people.

A different species, Culex tarsalis, is a West Nile virus vector.

Winnipeg insect-control superintendent Ken Nawolsky said since the city does not fog for mosquitoes every year, it tends to hold on to supplies of the pesticide. The manufacturer doesn't even make it every year, he said.

The city hadplannedto end malathion use next year and switch to DeltaGard, a more expensive but less controversial fogging agent. DeltaGard is approved for use in the U.S. and is awaiting a green light in Canada.

"Winnipeg and othermunicipalitiesthat do currently usemalathionare in the same boat right now," WinnipegMayor Brian Bowman said.

The mayor said he's looking forward to the end of malathion use but believes Winnipeggerswant nuisancemosquito fogging to continue.Winnipeg's summers are short, he said.

Nawolsky said Winnipeg would have to engage in extensive public consultations before it considers an end to fogging for nuisance mosquitoes.