REVISED (8/13/2007)

Environmental Analysis for the Proposed Revision to the Pesticide 

Commitment of the 1994 Ozone SIP for the Ventura County 

Nonattainment Area 

 

ARB received a number of public comments after the May 7, 2007 release of 

staff’s proposed revision to the Pesticide Commitment of the 1994 Ozone SIP for 

the Ventura County Nonattainment Area (Ventura). In response to these 

comments, ARB staff revised the originally proposed SIP revision. The revised 

proposal is set forth in Appendix H (revised on 8/13/2007) to the Proposed State 

Strategy for California’s SIP for the Federal 8-hour Ozone and PM2.5 Standards 

(State Strategy). 

When the proposed State Strategy was released on May 7, 2007, the potential 

environmental impacts of the State Strategy were analyzed by ARB staff. The 

analysis is contained in Appendix E to the State Strategy. Among other things, 

Appendix E includes an environmental analysis of DPR’s 2008 pesticide element 

of the State Strategy, as well as an analysis of ARB staff’s originally proposed 

SIP revision for Ventura. 

ARB staff has now prepared a new environmental analysis for the newly 

proposed revisions to the Pesticide Commitment of the 1994 Ozone SIP for 

Ventura. The new analysis is set forth below. Comments received on this new 

analysis will be summarized and responded to as provided in ARB regulations 

(title 17, California Code of Regulations, section 60007). Although this is a new 

analysis for the revised proposal, the analysis also summarizes and responds to 

comments raising significant environmental issues that are contained in comment 

letter dated June 12, 2007 and submitted by the Center for Race, Poverty & the 

Environment (CRPE). CPRE’s June 12, 2007 letter asserts that staff’s 

environmental analysis on the originally proposed SIP revision is inadequate for 

various reasons. Although CPRE’s letter is directed to the original proposal, 

many of CPRE’s comments are relevant to the revised as well as the original 

proposal. Staff therefore believes it is appropriate to respond to these comments 

in order to provide full public disclosure of potential environmental impacts. 

Potential Air Quality Impacts on Ozone Formation 

Methyl bromide and methyl isothiocyanate-generating fumigants comprise 

approximately 50 percent of the pesticide VOC inventory in Ventura. These two 

fumigants have very low photochemical reactivity, indicating that they do not 

appreciably contribute to ozone formation. The remaining fumigants used in 

Ventura have greater photochemical reactivity and do contribute to ozone 

formation. This means that the proposed SIP revision will result in emissions in 

2008 of an additional 0.65 tpd of ROG that will make some contribution to ozone 

formation. 
Preliminary photochemical modeling indicates that Ventura County will need to 

be reclassified as a serious nonattainment area for the 8-hour ozone standard, 

which will result in a June 2013 attainment date. Based on the preliminary 

photochemical modeling, it is apparent that ozone formation in Ventura responds 

to both NOx and ROG reductions. Consequently, the proposed revision may 

have a significant adverse impact on air quality in the short term as it may slow 

down slightly the improvement in ozone levels as compared to fully achieving the 

pesticide emission reductions in the 1994 Ozone SIP. However, the revised 

proposal phases out the substitution rapidly over four years and so is structured 

to ensure that the substitution will not interfere with Ventura’s ability to attain the 

8-hour ozone standard by the deadline for “serious” nonattainment areas. 

Potential Toxic Impacts 

Four fumigants accounted for 87% of the pesticide VOC emissions in the Ventura 

nonattainment area during 2004: 1,3-dichloropropene, chloropicrin, methyl 

bromide, and metam-sodium. Emissions of these fumigants would be the most 

impacted by this SIP revision. DPR anticipates a negligible health risk from toxic 

exposure to the fumigant levels under all of the emission scenarios described in 

this SIP revision. Complementary regulatory requirements and oversight by three 

regulatory agencies provide a comprehensive system for protecting people from 

toxic exposure to fumigants. The U.S. Environmental Protection Agency specifies 

nationwide restrictions through label requirements. Fumigant labels specify 

legally binding instructions and restrictions pertaining to storage, disposal, first 

aid, air concentration limits, methods of application, worker protection, and 

environmental protection. 

In addition to the label requirements, DPR develops and implements more 

stringent statewide requirements. DPR’s statewide requirements for methyl 

bromide and 1,3-dichloropropene include buffer zones, air concentration or use 

limits, application method restrictions, and worker protection provisions (Title 3, 

California Code of Regulations, Sections 6450, 6450.1, 6450.2, 6450.3; DPR 

2002). As described below, DPR is in the process of assessing the risk and 

developing mitigation measures for chloropicrin and metam-sodium. All four 

fumigants are “restricted materials” in California. As restricted materials, they 

require a permit issued by the county agricultural commissioner prior to use and 

can only be applied under the supervision of a certified applicator. State law 

requires county agricultural commissioners to evaluate local conditions prior to 

issuing restricted materials permits. Based on his evaluation of local conditions, 

the Ventura County agricultural commissioner includes additional restrictions on 

the permits for chloropicrin and metam-sodium. These permit conditions include 

buffer zones, tarpaulins for chloropicrin applications, and sprinkler systems for 

metam-sodium to be used in the event odors are detected (Ventura County 

Agricultural Commissioner). 
The statewide requirements described above are the result of DPR’s 

comprehensive risk assessment and risk management process. This process 

includes a toxicological and exposure evaluation, and mitigation as toxic air 

contaminants. DPR has completed risk assessments for 1,3-dichloropropene, 

methyl bromide and metam-sodium (as the methyl isothiocyanate breakdown 

product) (DPR 1997; Lim 2002; Rubin 2002). The risk assessment for 

chloropicrin is in progress. As part of the risk management process, DPR has 

identified acceptable exposure levels for 1,3-dichloropropene, methyl bromide, 

and methyl isothiocyanate-generating pesticides, based on the toxicology 

evaluation in the risk assessment. As described above, DPR has implemented 

statewide requirements for 1,3-dichloropropene and methyl bromide. DPR has 

proposed mitigation measures for methyl isothiocyanate-generating pesticides 

and plans to implement regulatory requirements later in 2007 (DPR 2007). The 

statewide requirements for these fumigants are designed to meet the acceptable 

exposure levels. The Ventura nonattainment area is one of the highest use 

counties for fumigants, and is an area that DPR closely evaluates. As part of its 

efforts to evaluate the effectiveness of the statewide regulatory requirements, the 

ARB (at the request of DPR) conducted monitoring in Ventura during 2005 and 

2006. Results of the monitoring show that air concentrations of 1,3-

dichloropropene and methyl bromide are acceptable (Table 1). The Office of 

Environmental Health Hazard Assessment (OEHHA) recommended a lower 

acceptable concentration for methyl bromide and the measured concentrations 

also meet these levels. Air concentrations should be lower than shown here once 

DPR’s VOC regulations are implemented, under all of the emission scenarios 

described in this SIP revision. 

Table 1. Methyl bromide and 1,3-dichloropropene air monitoring in Ventura 

during 8-week summer peak use season. 

 Measured 

Concentration (ppb) 

Acceptable Concentration 

(ppb) 

 2005 2006 DPR OEHHA 

Methyl bromide 

 Average of 5 sites 0.24 0.64 9.00 1.00 

 Highest site 0.39 0.88 9.00 1.00 

1,3-dichloropropene 

 Average of 5 sites 0.90 0.45 26.00 

 Highest site 2.33 0.84 26.00 

Potential Impacts on Ozone Depletion

Methyl bromide is an ozone depleting substance, and its production and 

importation are regulated under the Clean Air Act. Under the proposal, it is 

estimated that 0.6 tons per day more methyl bromide would be allowed from field 

fumigation in Ventura in 2008 than would be allowed under the 1994 Plan. 

Though methyl bromide is an ozone depleting substance, this revision will not 

have a significant adverse impact on the ozone layer. Ozone depletion is not a 
localized effect, and the additional methyl bromide permitted in Ventura County 

under the revision is negligible, approximately 0.0003 percent of the worldwide 

methyl bromide emissions. Also, it is likely that if the proposal were not adopted, 

additional methyl bromide emissions prohibited in Ventura would be allocated 

elsewhere in the country. 

The cumulative impact of methyl bromide emission on ozone depletion is 

addressed by the Montreal Protocol, which is implemented in the United States 

by U.S. EPA under Title VI of the federal Clean Air Act. U.S. EPA limits the total 

amount of methyl bromide consumed in the United States. The U.S. EPA has 

steadily decreased the amount of methyl bromide allowed as alternatives 

become available. 

Potential Impacts on Global Climate Change

Methyl Bromide has a Global Warming Potential (GWP) of 5, which is five times 

the global warming potential of carbon dioxide but approximately one-fifth of the 

GWP of methane. Methyl bromide (CH3Br) has an atmospheric lifetime of 

approximately 0.7 year. The proposed addition of less than 0.5 tpd methyl 

bromide, to be eliminated by 2012, is too small to have a significant adverse 

impact on climate change. 

Other Environmental Impacts

Except for the impacts discussed above, staff has not identified any other 

significant environmental impacts that would result from the proposed SIP 

revision. 

Project Alternatives

ARB staff evaluated the following alternatives to the proposed SIP revision. 

Alternative 1 – No Project 

CEQA documents typically contain an evaluation of the “no project” alternate. In 

this case, the “no project” alternative means that the ARB would not adopt the 

SIP revision and that an additional 1.3 tpd of pesticide emission reductions would 

occur in Ventura from implementation of DPR’s pesticide regulations. As 

discussed in Appendix H, staff is not recommending this alternative because it 

would have serious adverse economic impacts on agriculture in Ventura. Staff 

believes that avoiding these agricultural impacts outweighs the slight negative 

impact on ozone air quality discussed above. 
Alternative 2 – Substitute ROG reductions of less than 1.3 tpd 

Instead of providing ROG reductions of 1.3 tpd, ARB could provide lesser 

supplemental reductions of 1.0 tpd of ROG starting in 2008 with a phase down 

into 2012. This would make up part of the shortfall from DPR’s 2008 pesticide 

regulation. In order to mitigate the remaining 0.3 tpd of ROG, farmers would 

have to take agricultural fields out of production or use fewer pesticides, which 

would result in a loss in yield and farmland. Staff is not recommending this 

alternative because of the greater economic impacts associated with reduced 

productions or yield. 

Alternative 3 – Substitute ROG reductions of 1.3 tpd with no gradual phasedown prior to 2012 

This alternative would provide the same immediate relief from the potential 

economic impacts of reduced production or yield, but would continue that relief 

indefinitely compared to staff proposal. Research is currently underway to 

improve application methods. Within one to two years, advanced application 

methods could reduce ROG emissions from pesticides and provide the 

necessary reductions for Ventura’s ozone attainment in 2012. Nevertheless, 

staff is not recommending this alternative because it does not ensure that the 

significant adverse impact on air quality in the short term is fully mitigated by 

2012. 

Alternative 4 – Substitute ROG reductions of 1.9 tpd 

This alternative would provide ROG substitution of 1.9 tpd, which is the maximum 

amount of surplus ROG reductions that exists from ARB’s on-road motor vehicle 

program. Some persons who commented believe that 1.9 tpd for ROG 

substitution is necessary to fully mitigate the impacts on agriculture of DPR’s 

proposed pesticide regulation. These persons believe that DPR’s proposed 

estimate of a 1.3 tpd shortfall is too low because of their estimates of the recent 

growth in fumigated acreage. 

Staff is not recommending this alternative because DPR estimates that a 1.3 tpd 

substitution is sufficient to meet the 1994 SIP obligation. 

Feasible Mitigation Measures

As described above, the proposed SIP revision may have a significant short-term 

adverse impact on air quality, since it may slightly slow down improvement in 

ozone levels in Ventura. The previous section describes the alternatives to the 

proposed SIP revision that were evaluated by staff, and explains that staff was 

not able to identify any feasible alternatives that would substantially reduce the 

potential adverse impacts of the SIP revision while at the same time achieving its 

benefits. 
Staff also evaluated measures to mitigate the air quality impacts of the proposed 

SIP revision. Staff was unable to identify any feasible mitigation measures that 

would substantially reduce these impacts, while at the same time achieving the 

benefits of the SIP revision. However, it should be noted that the proposed SIP 

revision does incorporate mitigation measures that were not part of the original 

proposal released for public comment on May 7, 2007. The original proposal 

was to substitute 1.0 tpd of surplus ROG emission reductions in Ventura for 1.0 

tons of pesticide emissions. This was a long-term substitution with no 

termination date and no phase-out schedule. Staff’s revised proposal 

incorporates a phase-out schedule and a 2012 termination date in order to 

mitigate the air quality impacts of the SIP revision. The effect of the provisions 

on air quality is described in detail in Appendix H. 

Cumulative Impacts

Staff has also considered the potential cumulative impacts of the proposed SIP 

revision. With respect to air quality, evaluating cumulative impacts essentially 

means that the impact of an extra 1.3 tons of ROG emissions must be 

considered in combination with other sources of ROG emissions in the Ventura 

County Nonattainment Area. The nature of the photochemical modeling done for 

Ventura County analyzes the cumulative impacts of all know ROG emission on 

ozone formation. Consequently, staff did a cumulative analysis when 

determining the effect of the proposed SIP revision on ozone formation and 

attainment in Ventura. 

Summaries and Responses to Significant Environmental Issues

Following are summaries and ARB staff’s responses to the environmental issues 

raised in the June 12, 2007 comment letter submitted by the Center for Race, 

Poverty & the Environment (CRPE).

Comment in Section II, page 4: “...the AMAFs are based on unrepresentative 

field fumigation studies conducted in other states under cool soil conditions, 

which do not provide an accurate estimate of emissions from California 

fumigations conducted at high temperatures in the Central Valley during the peak 

ozone season from May to October. Studies conducted under worst-case 

scenarios have been excluded from the group of studies on which the regulation 

is based.”

Response: We have included in this analysis those studies that have been 

reviewed and accepted as sufficient quality to provide reliable results. The 

studies were conducted at a variety of locations under a variety of meteorological 

conditions and over the entire year. The variety of locations, application 

methods, and meteorological conditions are varied in large part due to the 
diverse nature of agriculture in California. The current set of studies used in this 

analysis is the database available. 

We agree in concept that temperature is important. However, DPR’s work with 

methyl bromide applications throughout the year found that winter applications 

can show high flux, high emissions, and high air concentrations. In fact, analysis 

of the relationship between Julian date of the application (as a surrogate for 

temperature) and the percentage of emissions (emission ratio) for monitored 

applications shows no significant relationship between emissions and day of 

application. A measurable temperature effect should be clearly discernable by a 

regression analysis. Thus, a simple, clear relationship between temperature and 

flux is not supported by the DPR methyl bromide database. More likely many 

factors act together and, thus, the more global approach that DPR has taken to 

estimating the AMAF’s is more appropriate. 

A plot of the methyl bromide emission ratios is shown below. Note the complete 

lack of trend for the tarp broadcast data. In particular, the February 13, 1997 

application has an emission ratio of 9.8%. This could be argued to support the 

low temperature, low flux theory. However, the July 25, 1998 application shows 

an emission ratio of 6.8%. It is also clear the tarp bed application method shows 

a high emission ratio no matter when the application is made. In fact, the tarp 

bed applications in December show a 100% emission ratio, similar to those 

applications made in June and October. The methyl bromide database is the 

largest available and likely reflects trends in flux and emission ratios for other 

fumigants. 

jul date

em ratio

0 100 200 300 400

100

80

60

40

20

0

nontarp deep

tarp broadcast

tarp bed

method

Scatterplot of em ratio vs jul date
Comment: The memorandum from Susan Kegley to Brent Newell, dated June 

12, 2007, recommends “Base emission estimates on all available studies with 

valid experimental procedures that are relevant to the currently allowable 

applications methods.” 

The memorandum provides four examples of unrepresentative and excluded 

studies. “For example, the chloropicrin fumigation that was conducted in 

Washington State was done on a night that the air temperature actually dropped 

below freezing. It is very likely that the low emission rate observed for this 

fumigation had nothing to do with the application method and everything to do 

with the fact that the air temperature was nine degrees below freezing.”

Response: This comment inaccurately reports the study results and does not 

mention that the 33.8% emissions shown in the Washington results is similar to 

the 36.5% emissions shown in the Florida results. The temperature during the 

day when the application was actually made was 57 degrees F. The temperature 

on the night immediately following the application was 46 degrees F. The night 

air temperatures during the majority of the study were above 37 degrees F and 

the maximum night temperature was 57 degrees F. The average night air 

temperature was 40 degrees F. The average day air temperature was 48 

degrees F. When “...air temperature was nine degrees below freezing...,” this 

event occurred 2 weeks following the application during the second to last 

sampling interval. By that sampling interval the majority of the 34% of applied 

mass lost was already measured. The 33.8% emissions shown in Washington 

results are similar to 36.5% emissions shown in the Florida results. These were 

both broadcast tarp applications. The air temperatures during the Florida study 

were 15 to 20 degrees F warmer yet the mass loss results are similar to the 

Washington study. Thus, the commenter’s views are not supported by the data. 

Comment: “None of the chloropicrin studies were conducted in California... Soil 

type is one of the factors that controls the amount of fumigant released from the 

soil during a fumigation...”

Response: It is true that none of the chloropicrin studies were conducted in 

California. We agree in concept that soil type is among many factors that has an 

effect on emissions. In fact, the Arizona studies were conducted on sandy soil 

that in concept could result in a higher loss than most soils in California. 

However, we will reiterate that DPR has taken a global approach to estimating 

the AMAF’s for several reasons including the lack of studies to quantify what are 

essentially small scale refinements of the AMAF’s and the fact that when the 

AMAF’s are used to estimate the total VOCs the scale is very large. There is no 

practical way to incorporate soil type into the estimates. 

Comment : “In contrast, industry studies with glaring experimental errors were 

accepted for use in the emission estimates. For example, the soil study used to 

estimate emissions from “standard sprinkler” applications of metam sodium, had 
samplers placed nearly perpendicular to the wind direction, thus ensuring the 

maximum concentrations could not be measured.”

Response: No studies with “glaring experimental errors” were used in the AMAF 

development. It is true that the standard sprinkler study, and also the standard 

shank study, had a sampler layout that was not optimal. The sampler layout was 

an attempt to capture the predominant wind direction. However, studies 

conducted over several days typically have no true predominant wind direction. 

It should be noted that both studies were done according to Good Laboratory 

Practices and were submitted, accepted, and used to characterize off-site 

exposure by the U.S. Environmental Protection Agency (U.S. EPA) in their 

Metam Sodium Risk Assessment. Thus, both U.S. EPA and DPR have reviewed 

these studies. Further, the layout of the samplers in both those studies actually 

caused very high emission estimates to be obtained for some sampling intervals 

due to inherent shortcomings of the computer model. As a result, the emissions 

estimated from those studies may be overestimated, not underestimated as the 

commenter suggests. 

Comment: “Studies like this should be discarded in preference to studies with 

valid experimental procedures such as the ARB/DPR study conducted in 1993 

where the experiment was done correctly and captures the representative 

emissions from a worst-case scenario application. In the current emission 

estimate, this ARB study is not used.”

Response: The 1993 ARB/DPR study is not used for several reasons: 

1) The study was not designed to estimate flux: 

a) Only four samplers were used, one on each side of the field for an 84 acre 

field. This is not sufficient to characterize the flux. 

b) Only summarized weather data was available, no on-site weather data 

was reported. 

c) The sampling intervals span sunrise and sunset. In order to accurately 

estimate emissions, the sampling periods must separate the day and night 

periods. 

2) There are significant events that cast doubt on the reported air concentrations: 

a) Samples from sampling periods 3 and 4 were left in an ice chest over the 

weekend in air temperatures over 100 degrees F. No dry ice was left in 

the ice chest by the time the samples were retrieved. Therefore, those 

samples are not valid. 

b) The west sample from sampling period 5 was left by mistake in the freezer 

for 10 weeks and then analyzed. The storage stability over 10 weeks was 

not evaluated. 
Comment in Section II, page 4: ...”natural variability in flux rates (the rate at 

which the fumigant escapes from the soil) is large, thus a single study – or even 

several studies – will not provide an accurate estimate of actual emissions.” 

The memorandum from Susan Kegley to Brent Newell, dated June 12, 2007, 

recommends “Use high-end emission estimates from these studies to estimate 

VOC emissions during the summer ozone season.”

Response: We agree that the variability in flux rates (emissions) between 

applications is large. For fumigants and application methods with multiple 

studies, the standard deviations of the emissions are approximately 50%. DPR 

has chosen to use the average flux rates to estimate emissions for three 

reasons. First, the emission inventory represents the aggregate emissions from 

all agricultural and structural pesticide applications within a region over several 

months. The average flux rates represent the most accurate estimate of 

aggregate emissions. Second, all pesticide applications included in DPR’s 

inventory represent their most accurate and consistent estimate of emissions, for 

both the base year and subsequent years. Using a consistent method to estimate 

emissions is essential for making relative comparisons and determining 

compliance with the SIP commitments. Using the most accurate estimates for 

some applications and high-end estimates for other applications would skew the 

inventory and make relative comparisons unreliable. Third, even if high-end 

emission estimates were to be used, they would affect both current emissions 

and emissions for the 1991 base year. Estimates of the 1991 base year 

emissions are generally more uncertain than current emissions. Therefore, it 

would probably be appropriate to apply a larger uncertainty factor to the 1991 

base year than current emissions, and the emission reductions achieved would 

be larger than currently estimated using the average flux rates. 

Comment: The memorandum from Susan Kegley to Brent Newell, dated June 

12, 2007, recommends “Determine 4-hour and 8-hour averages and use them to 

estimate peak ozone-forming emissions.”

Response: Data is not available for all but a few pesticides to determine 4-hour 

or 8-hour peak emissions. Using a consistent method to estimate emissions is 

essential for making relative comparisons and determining compliance with the 

SIP commitments. Using peak emissions for some, but not all applications would 

skew the inventory and make relative comparisons unreliable. 

Comment in Section II, page 4: “DPR has not presented any evidence supporting 

its estimates of historical fumigant application methods, nor has it made public 

the details of the process by which this information was obtained.”

Response: DPR provided a detailed explanation of its method for determining the 

frequency of use of historical fumigant application methods in its memorandum 
from Barry, Spurlock, and Segawa to Sanders, dated April 6, 2007. The 

explanation from this memorandum is excerpted here. 

In California, all agricultural and commercial pesticide applications must be 

reported. County agricultural commissioners and DPR compile these PURs into a 

database. The PUR database includes the identity of the product applied, the 

amount applied, location, date, crop/site treated, and other information. DPR 

uses the pounds of product applied recorded in the PUR database to calculate 

the VOC emissions for each pesticide application included in the pesticide VOC 

emission inventory. The PUR database contains general information about the 

application method (i.e. air, ground, or other), but it does not indicate the specific 

application method. Therefore, another adjustment is needed to account for the 

use of each fumigant application method. 

In general, different crops use different fumigant application methods. Roush 

(2006) found that the different nonattainment areas have different crops 

responsible for the majority of pesticide VOC emissions. Therefore, each 

nonattainment area should have a different set of adjustment factors to 

characterize the use of fumigant application methods. While the application 

method depends on the crop to be planted, other factors such as soil type, cost, 

and equipment availability also influence the choice of application method. For 

example, strawberries always use a shallow application method. However, the 

tarp broadcast and tarp bed application methods are both commonly used for 

strawberries, and these application methods have different emissions. Therefore, 

the type of crop is an unreliable surrogate to identify the fumigant application 

method in some cases. 

DPR proposes to use a variety of methods to estimate the use of each of the 

fumigant application methods (method use fraction). The method for 1,3-D is the 

most accurate. As required under DPR’s 1,3-D management plan, the registrants 

maintain records of the specific application method for all 1,3-D applications. 

Johnson (2006) describes the May–October method use fractions, based on the 

registrants’ data. 

Lawson (2006) provides a survey of metam-sodium practices by several dozen 

growers and applicators in certain areas of the state. This survey includes a 

compilation of the application methods. The survey includes specific information 

for three nonattainment areas, as well as the top ten counties. DPR uses the 

percentage breakdown described in Lawson (2006) on the use of the various 

metam-sodium applications for the San Joaquin Valley, Southeast Desert, and 

Ventura nonattainment areas. DPR uses the breakdown for the top ten counties 

described in Lawson (2006) as a surrogate for the Sacramento Metro 

nonattainment area, and Ventura as a surrogate for the South Coast 

nonattainment area. 

Similar to the approach described by Stangellhini (2006a, 2006b; Appendix 1), 

DPR uses information from the PURs to estimate the May–October method use 

fractions for methyl bromide and chloropicrin based on the following 

assumptions: 
• For 1990/91 methyl bromide and chloropicrin applications, all row, vegetable, 

and nursery crops (except strawberries) were fumigated using a shallow 

injection broadcast method with a high permeability tarpaulin or no tarpaulin. 

• For 1990/91 methyl bromide and chloropicrin applications, one-half of the 

strawberry applications were conducted with a shallow injection broadcast 

method and a high permeability tarpaulin, and one-half of the strawberry 

applications were conducted with a shallow injection bed method and a high 

permeability tarpaulin. 

• For 1990/91 methyl bromide and chloropicrin applications, all tree and vine 

crops were fumigated using a deep injection method with a high permeability 

tarpaulin or no tarpaulin. 

Comment in Section III.A., page 8: “it is inconceivable for the Environmental 

Impact Analysis to assert that an increase in toxic fumigant use will have no 

impact on the environment.”

 

Comment in Section III.A.1., page 8: “Substantial evidence shows that neither 

DPR regulations nor EPA labeling requirements adequately prevent acute or 

chronic health impacts.”

Comment: The memorandum from Anne Katten to Brent Newell and Susan 

Kegley, dated June 6, 2007, states that for methyl bromide “OEHHA has 

recommended that regulations should be designed to reduce sub-chronic 

exposure of the general public and adjust workers below 1 ppb and 2 ppb 

respectively to prevent neurobehavioral effects, while DPR’s current regulations 

are only designed to control exposures to 9 ppb for the general public and 16 ppb 

for fumigation workers.”

Response: These comments are addressed in the section of this Environmental 

Analysis entitled “Potential Toxic Impacts.” 

Comment in Section III.A.2, page 9: “Substantial evidence demonstrates that 

fumigants cause acute chronic impacts to human health and to threatened and 

endangered species.” “These fumigants also may inflict substantial harm on the 

California red-legged frog, which is found in Ventura County and listed 

endangered under the federal Endangered Species Act.”

Response: Pesticide use restrictions implemented under a court injunction and 

order specifically address red-legged frog populations. On October 20, 2006, the 

U.S. District Court for the Northern District of California imposed no-use buffer 

zones around California red–legged frog upland and aquatic habitats for certain 

pesticides. This injunction and order will remain in effect for 66 pesticides 

(including the fumigants 1,3-dichloropropene and metam-sodium) until the U.S. 

Environmental Protection Agency goes through formal consultation with the Fish 

and Wildlife Service on each of the 66 pesticides, and the Fish and Wildlife 
Service issues a Biological Opinion including a “not likely to adversely affect” 

statement for the pesticides. Under the injunction and order, no-use buffer zones 

of 60 feet for ground applications and 200 feet for aerial applications apply from 

the edge of California red-legged frog habitats, including habitats in Ventura 

County. 

Specifically for Ventura County, California Red-legged frogs occur in three 

Critical Habitat units: Ventura 1 – Matilija Creek, Ventura 2 – San Antonio Creek, 

and Ventura 3 – Piru Creek as designated by the U.S. Fish & Wildlife Service in 

2006. Additional habitat is found within one Non-critical Habitat Section near the 

southeast corner of the county. During 2001 – 2005, there was no reported use 

of 1,3-dichloropropene, chloropicrin, metam-sodium, or methyl bromide within a 

one mile of any of the habitats, well outside the 60-foot or 200-ft buffers required 

under the court order. DPR’s evaluation, in consultation with California 

Department of Fish and Game, indicates that non-target wildlife exposure to 

these fumigants in Ventura. 

References 

DPR. 1997. Risk Assessment of 1,3-Dichloropropene, January 10, 1997. 

California Department of Pesticide Regulation. 

DPR. 2002. California Management Plan: 1,3-Dichloropropene, January 30, 

2002. California Department of Pesticide Regulation. 

DPR. 2007. Mitigation Proposal, Control of Off-Site and Bystander Short-Term 

Exposure to Methyl Isothiocyanate (MITC) from Metam-Sodium and MetamPotassium Applications, January 5, 2007. California Department of Pesticide 

Regulation. 

Roush, T.L. 2006. 2006 Update to the Pesticide VOC Emission Inventory: 

Estimated Emissions 1990-2004. Memorandum to John Sanders, October 24, 

2006. California Department of Pesticide Regulation. 

Rubin, A.L. 2002. Evaluation of Methyl Isothiocyanate as a Toxic Air 

Contaminant, Part C – Human Health Assessment, August 2002. California 

Department of Pesticide Regulation. 

Ventura County Agricultural Commissioner. Permit Conditions – Metam Sodium 

and Metam Potassium. Ventura County Agricultural Commissioner. 

Ventura County Agricultural Commissioner. Permit Conditions – Chloropicrin. 

Ventura County Agricultural Commissioner.