SACRAMENTO -- The California Department of Pesticide Regulation will propose new methyl bromide regulations to restrict levels of the fumigant that may persist in the air for several weeks. The new rules would impose the first geographic use limits on methyl bromide in the nation, and DPR will call on federal regulators to adopt a national standard based on the California model.
The proposed regulations are aimed at enhancing protection for workers and others who face potential exposure when multiple fumigations occur in the course of several weeks -- also known as "seasonal" exposures.
DPR has not found any imminent health hazard to communities from seasonal exposures to methyl bromide in recent years, based on air monitoring of high-use areas. In 2001, the highest ambient air samples were slightly more than half the level at which DPR would take action under the new rules.
"Our proposed regulations are preventive, not reactive," said DPR Director Paul Helliker. "Air monitoring data, combined with the best scientific evidence available, show that seasonal air levels of methyl bromide pose no immediate health concerns for communities. At the same time, we want to enhance protection for workers who may face ongoing exposure to methyl bromide from field fumigation."
California agriculture has dramatically reduced its use of methyl bromide in recent years, and the state no longer leads the nation in field fumigations. "But some methyl bromide applications may well continue due to a lack of alternatives," said Helliker. "DPR's goal is to ensure that any future uses of methyl bromide in California will continue to provide a sufficient margin of safety for workers and the public," he said.
"California now has the most comprehensive, stringent restrictions on methyl bromide in the country, and we urge the U.S. Environmental Protection Agency to adopt our rules as a national standard," said Helliker. "While affording greater protection for all, this would also provide a level playing field for agriculture and create more incentive to find safer and more effective alternatives to methyl bromide."
DPR previously adopted regulations aimed at limiting short-term (24-hour) exposures to methyl bromide in the air to no more than 210 parts per billion (ppb). While maintaining that same short-term standard, DPR now proposes an additional regulatory action level averaging no more than 9 ppb for seasonal (four-to-eight-week) exposures for children, and 16 ppb for adults. (One part per billion is equivalent to one second of time in about 32 years, or one drop of liquid in a full tanker of a gasoline delivery truck.) DPR's action levels for both short-term and seasonal exposures include a 100-fold margin of safety.
To prevent air levels from exceeding these seasonal regulatory standards, DPR proposes to limit any single township to total applications of less than 270,000 pounds a month. (A township is a survey unit of 36 square miles.) In 2001, the highest monthly application occurred in a township on the border of Santa Cruz and Monterey counties. That township had total applications of 202,000 pounds in one month.
DPR already requires buffer zones and other precautions near schools and other sensitive sites that meet the 9 ppb air standard for children. The new rules will mandate more protective gear and work-time restrictions for laborers (based on the 16 ppb adult standard).
DPR expects to post the proposed regulations online
at www.cdpr.ca.gov
next week, pending approval by the Office of Administrative
Law, which reviews all state regulatory proposals. A
public comment period will follow. DPR also plans to
schedule public hearings in Sacramento, Ventura, and
Salinas. Dates and other details will be announced when
the regulations are posted online. Fact sheets are posted
at www.cdpr.ca.gov/docs/emon/methbrom/mb_main.htm.
DPR's proposed regulations are based on numerous scientific studies and extensive air monitoring conducted since the early 1990's. DPR scientists completed a risk assessment for methyl bromide in 1999 and sent their scientific document to the National Academies of Science (NAS) for review and comment. An NAS panel endorsed DPR's findings for short-term exposure action levels.
In 2000, DPR imposed new regulations for methyl bromide that included buffer zones, advance notification for field fumigations, and other protections. The rules were based on the 210 ppb standard for short-term exposures. No regulatory action level was set for seasonal exposures, due to a lack of scientific data, but DPR used a provisional "target level" of 1 ppb to identify areas with the highest seasonal air levels of methyl bromide.
DPR scientists then began to review air monitoring data and assess the need for additional regulatory safeguards. The NAS panel supported DPR's approach. The panel also recommended an additional toxicology study to establish subchronic (seasonal) action levels for methyl bromide exposure.
DPR's methyl bromide regulations have been the subject of lawsuits by both environmental and agricultural interests. To resolve that litigation, DPR agreed to reassess the regulations' potential economic impact on farmers, and to consider seasonal exposure standards. The rules imposed in 2000 were readopted as emergency regulations, pending introduction of a new regulatory package this year.
After reviewing all available data, DPR scientists recommended seasonal exposure action levels of 9 ppb for children, and 16 ppb for adults. The recommendation was based on studies considered for DPR's 1999 risk assessment, supplemented by a recent study submitted by the methyl bromide industry to address specific subchronic exposure issues.
However, some industry advocates have argued that DPR should allow exposure levels of up to 36 ppb for children and 64 ppb for workers. Some environmental advocates favor a 1 ppb level. DPR expects to hear more on this issue during the public comment period.
DPR's actions on methyl bromide are separate from regulatory actions under the federal Clean Air Act and the Montreal Protocol, an international agreement. Based on evidence that methyl bromide depletes the ozone layer in the stratosphere, the United States has agreed to end production of the fumigant by 2005. However, federal and international authorities are now considering "critical exemptions" to allow continued use when no feasible alternatives exist.
Meanwhile, DPR and California agriculture have already made significant strides in reducing methyl bromide use. California used 42 percent of all methyl bromide produced in the United States for farm field fumigation in 1997, according to U.S. EPA. By 2001, California's farm field use had fallen to 27 percent of the national use, compared to 45 percent for Florida, according to industry estimates provided to U.S. EPA.
That decline corresponds to DPR use reports that show methyl bromide use in California fell from more than 15 million pounds in 1999 to 6.6 million pounds in 2001. Factors contributing to the decline include increasing DPR restrictions, use of other fumigants, research on less-toxic alternatives supported by DPR and industry; and reductions mandated by the Clean Air Act.
One of six departments and boards within Cal/EPA, DPR regulates the use of pesticides to protect human health and the environment.
FLEX YOUR POWER! For simple ways to reduce energy demand
and cost, see www.flexyourpower.com.
Back
to News and Publications
