Despite safety assurances, controversy swirls around pheromone spray.

Who knew that a hungry little moth could cause so much drama? The latest chapter in the debate over the state’s plan to control the pest involves the health of the marine sanctuary, the safety of little-known chemicals, and a request for a court order to halt the spraying.

For the second time in just over a month, planes are poised to spray a synthetic pheromone product over 60 miles of the Monterey Peninsula from Marina to Pacific Grove. The California Department of Food and Agriculture (CDFA), in cooperation with the US Department of Agriculture (USDA), has initiated the aerial spraying program to combat the invasive light brown apple moth, which has been detected in 11 California counties. Officials fear the pest could cause widespread agricultural damage.

But some locals worry about the impacts the pheromone product could have on residents and wildlife – particularly in the protected Monterey Bay National Marine Sanctuary (MBNMS). While state officials maintain that the product will not enter sanctuary waters, MBNMS officials disagree.

The USDA’s environmental assessment states that products like Check Mate can be moderately toxic to marine invertebrates at higher concentrations than the application rate being used locally. CDFA officials counter that the spray is applied in quantities nearly too small to detect, much less poison marine life.

For the first round of spraying, Sept. 9-13, MBNMS staff did not require the CDFA to obtain a pollution discharge permit, based on the state agency’s claim that the spray would not reach sanctuary waters.

Still, sanctuary staff placed monitoring devices along the shoreline. A certified lab analysis found small quantities of urea, indicating that the pheromone product had reached the water. Sanctuary officials reversed their earlier decision and concluded that the CDFA would need a permit to continue spraying.

“It looked like some level of the discharge did occur,” says Deirdre Hall, the sanctuary’s resource protection specialist.

CDFA, however, disagrees. Agency staff placed cards along the shoreline before the September spraying, and lab tests have concluded that the pheromone product did not land on them, says CDFA spokesman Steve Lyle. “In the unlikely event the material would reach the ocean, it’s nontoxic to sea life and doesn’t present a risk,” he says.

At MBNMS’s request, UC Davis’ Marine Pollution Studies Laboratory independently  tested the toxicity of Check Mate LBAM-F, one of the two pheromone formulas being sprayed on the Peninsula. Lab staff put a small dose of the product (reflecting the aerial application rate) into a beaker of seawater containing larval mussels and monitored their development for 48 hours. “There was no effect on the survival or the development of the organism,” says researcher Bryn Phillips.

Based on the results, MBNMS issued CDFA a discharge permit on Oct. 5.

CDFA officials state repeatedly that there is no scientific evidence to suggest that the pheromones are harmful to people or the environment (sexually frustrated LBAM and other “leafroller” moths excepted). But to chagrin of concerned locals, the products being sprayed on the Peninsula contain more than just synthetic pheromones.

The Check Mate OLR-F label states that the product is made up of about 76 percent inert ingredients. Steve Hartmeier, president of product manufacturer Suterra, Inc., says that 73 percent is water. The other 3 percent, he says, comprise an “inert organic microcapsule” that controls the release of the pheromone over a 30-day timeframe.

Suterra has provided the list of inert ingredients to the US Environmental Protection Agency (EPA) and the state Department of Pesticide Regulations. The company would not provide the list to the media, asserting that the ingredients were trade secrets. However, on Sept. 28, The Santa Cruz Sentinel published the list of four inert ingredients in Check Mate OLR-F, citing the EPA as a source. Later, the newspaper removed the list from its website. The list does remain publicly available: A photocopy of the story was obtained on Oct. 9 from the Santa Cruz public library.

Two of the chemicals are on the EPA’s list of inert ingredients not believed to adversely affect public health or the environment.

A third disclosed ingredient, tricaprylyl methyl ammonium chloride, is on the EPA’s list of inerts of unknown toxicity. According to the Pesticide Action Network North America, a San Francisco-based public interest organization advancing alternatives to pesticides, the compound is considered “moderately toxic” to insects, “highly toxic” to fish and “very highly” toxic to zooplankton.

CDFA officials maintain that the products are applied in such low doses as to have little to no impact on marine life.

The US government has not established water quality standards for a fourth disclosed inert ingredient, poly-methylene polyphenyl isocyanate. The chemical’s Material Safety Data Sheet (MSDS) describes it as a health hazard when ingested, inhaled or exposed to skin – but it does not identify the concentration at which the chemical causes harm. Symptoms of overexposure include breathlessness, coughing, chest discomfort, irritation of the mucous membranes and asthma-like conditions. The federal Occupational Safety and Health Administration (OSHA) adds itchy eyes and irritation of the nose, throat and skin to the list of symptoms.

Whether a result of the first aerial application or not, more than 100 Peninsula residents reported feeling ill after the planes released the synthetic pheromones in September. “The symptoms that [polymethylene polyphenyl isocyanate] causes are remarkably similar to those that people are reporting,” says David Dilworth of Helping Our Peninsula’s Environment (HOPE).

HOPE filed a lawsuit against the state in late September, alleging that aerial spraying injures humans and the environment. State and federal officials maintain that the products are safe and necessary to combat the moth.

On Oct. 5, HOPE requested a temporary restraining order to stop the spraying as the lawsuit moves forward. At press time Dilworth said HOPE would be filing additional evidence to support its= case, including a list of the inert ingredients and a physician’s comments. As of late Tuesday, the Monterey Superior Court judge has not ruled on HOPE’S request. The second spray, however, was rescheduled to begin Oct. 10 (after the Weekly went to press) due to a one-day weather delay.

Last week, the Seaside and Monterey City Councils adopted resolutions opposing the spraying until the CDFA can provide studies showing that the Check Mate products are not harmful. The resolutions also ask the agency to do a better job of communicating with the public.