Department of Pesticide Regulation Logo 
Winston H. Hickox
Secretary for

Department of Pesticide Regulation

Paul E. Helliker, Director
830 K Street - Sacramento, California
95814-3510 -

   California Notice 99-6

California State Seal
Gray Davis

January 1, 1999 THROUGH June 30, 1999

California regulations require the Department of Pesticide Regulation (DPR) to investigate all reports of actual or potential significant adverse effects to people or the environment resulting from the use of pesticides. If an adverse impact occurred or is likely to occur, the regulations require DPR to reevaluate the registration of the pesticide.

California Code of Regulations (CCR) section 6221 specifies the factors under which DPR may initiate a reevaluation: (a) public or worker health hazard; (b) environmental contamination; (c) residue over tolerance; (d) fish or wildlife hazard; (e) lack of efficacy; (f) undesirable phytotoxicity; (g) hazardous packaging; (h) inadequate labeling; (i) disruption of the implementation or conduct of pest management; (j) other information suggesting a significant adverse effect; and (k) availability of an effective and feasible alternative material or procedure which is demonstrably less destructive to the environment. Often, ongoing DPR reviews trigger a reevaluation. Reevaluation triggers also include state and county pesticide use surveillance and illness investigations, pesticide residue sample analyses, environmental monitoring activities, and information from other state or federal agencies.

When a pesticide enters the reevaluation process, DPR reviews existing data. DPR requires registrants to provide additional data to determine the nature or extent of the potential hazard or identify appropriate mitigation measures, if needed.

DPR concludes reevaluations in a number of different ways. If the data demonstrate that use of the pesticide presents no significant adverse effect, DPR concludes the reevaluation without additional mitigation measures. If additional mitigation measures are necessary, DPR adopts regulations to mitigate the potential adverse effect. If the adverse impact cannot be mitigated, DPR cancels or suspends the registration of the pesticide product.

This report complies with the requirements of CCR section 6225. CCR section 6225 requires DPR to prepare a semiannual report describing pesticides evaluated, under reevaluation, or for which factual or scientific information was received, but no reevaluation was initiated. The report contains two sections:

I. Formal Reevaluation - initiated when an investigation indicates a significant adverse impact has occurred or is likely to occur (page - 2); and

II. Preliminary Investigations (Evaluations) - products or active ingredients for which DPR receives possible adverse, factual, or scientific information, but no reevaluation has been initiated (page - 6).

I. FORMAL REEVALUATION - undertaken when investigations indicate a significant adverse impact has occurred or is likely to occur.


Applicators use copper naphthenate as a fungicide and wood preservative to control fungal decay and insect attack. DPR placed products containing copper naphthenate into reevaluation on December 28, 1995, based upon concerns regarding use of the product indoors. DPR's Worker Health and Safety Branch received a number of reports of illnesses following exposure to the indoor use of pesticide products containing copper naphthenate. The illnesses appear to be associated with inhalation exposure resulting in nausea, dizziness, and headaches. In some cases, the structure could not be occupied for an extended period of time following treatment.

DPR reviewed the labels of all currently registered products containing copper naphthenate in order to determine which presented a potential hazard. In
February 1996, DPR discussed its concerns regarding copper naphthenate with the U.S. Environmental Protection Agency (U.S. EPA). Based upon DPR's information, U.S. EPA decided that indoor use of copper naphthenate was of national concern, and therefore, best addressed by U.S. EPA. U.S. EPA met with representatives of the Naphthenate Salts Research Task Force (Task Force) to discuss this issue. During that discussion, U.S. EPA expanded the issue to include pesticide products containing zinc naphthenate. On October 1996, the Task Force sent U.S. EPA a mitigation proposal. U.S. EPA responded to the Task Force's proposal in December 1996, after consultation with DPR. U.S. EPA and DPR found certain elements of the proposal to be acceptable; however, the proposal needed further modification.

In January 1997, U.S. EPA received a letter stating that the Task Force would not be supporting continued indoor use of either copper or zinc naphthenate pesticide products. In March 1997, the Task Force submitted amended labels to both U.S. EPA and DPR for products registered to the three basic manufacturers of copper and zinc naphthenate. The manufacturers revised the labels of their products to delete all indoor uses and to add the statement "For Exterior Use Only." In addition, a statement has been added requiring the use of respirators during prolonged or frequent use of the product. The Task Force members also added a toll free number and the statement "In case of medical questions, emergencies, or accidents involving this product, call 1-800-XXX-XXX" to the labels of their products. DPR reviewed the amended labels and sent comments to U.S. EPA. DPR cannot accept the amended labels until they have been accepted by U.S. EPA.

Registrants have amended the labels of 18 currently registered copper naphthenate to comply with U.S. EPA and DPR requirements. The registrant of one copper naphthenate product intends to withdraw the registration of its product for 2000. DPR is reviewing amended labels for the remaining six copper naphthenate products.

CYFLUTHRIN -- 37 Products

The pesticide active ingredient cyfluthrin is a non-systemic pyrethroid insecticide registered for use on numerous field, fruit, and vegetable crops, including citrus. In addition, DPR registers pesticide products containing cyfluthrin for use on lawns and ornamental plants, animals, and around industrial, institutional, agricultural, and household structures.

DPR initiated the reevaluation on May 8, 1998 based on its investigation of a May 1997 outbreak of respiratory irritation reported among orange harvesters exposed to residues of cyfluthrin in Tulare County and other pesticide illness reports related to cyfluthrin. As a part of the investigation of the Tulare County incident, DPR=s Worker Health and Safety Branch conducted two separate inhalation monitoring studies in orange groves during orange harvest. DPR determined that since dust and pollen are a part of the normal working environment, something different in the work environment led to the worker=s respiratory irritation symptoms. DPR feels that the application of cyfluthrin to the citrus groves close to harvest led to the respiratory symptoms experienced. DPR compiled the results of its monitoring study in AHealth and Safety Report, HS - 1765." DPR maintains a pesticide illness registry, the Pesticide Illness Surveillance Program (PISP). From 1990-1995, DPR recorded 108 illness/injury cases related to cyfluthrin into the PISP database. Of the 108 cases, 15 were related to the agricultural use of cyfluthrin. The remaining 93 cases involved application of the pesticide in and around structures.

As a part of the reevaluation, DPR required registrants to submit the results of an inhalation irritation threshold study. In mid-September 1998, the basic manufacturer of cyfluthrin submitted the results of several studies and journal articles concerning the respiratory irritation of cyfluthrin. On October 29, 1998, DPR met with the basic manufacturer to discuss the cyfluthrin reevaluation. At that meeting, DPR agreed to review the submitted studies and journal articles before deciding whether to require additional data. After reviewing the data, DPR determined that although limited in scope the data could be used to generate a no-effect level for risk assessment. The study was limited by the constraints from the Human Subjects Committee which would not permit a double blind study to be carried out on human subjects.

In May 1999, the Agricultural Reentry Task Force commenced a study to assess the exposure to workers from cyfluthrin residues in a treated orange orchard. The study will monitor air levels and observe the levels of dermal exposure for workers harvesting oranges. Preliminary results of the study are expected to be available in August 1999.

DIPHACINONE -- 2 Products

DPR registers products containing the active ingredient diphacinone for use in and around homes, agricultural, and industrial buildings, and in sewers for the control of Norway rats, roof rats, and house mice. DPR registers 51 products containing diphacinone. Of the currently registered products, 49 are intended for end-use and contain 0.2 percent or less diphacinone. Containing one percent and two percent diphacinone, the two remaining products are concentrates intended for use in the formulation of end-use rodenticides.

DPR initiated a reevaluation of products containing one percent or more diphacinone based on its review of acute toxicity data recently submitted to support the registration of a one percent diphacinone product. DPR found the submitted acute dermal toxicity and primary dermal irritation studies to be unacceptable. Without the submission of acceptable acute toxicity studies, DPR is unable to determine whether the precautionary statement currently on the label of the product adequately identifies
acute toxicity hazards.

After a search of the database, DPR determined that no acute toxicity studies are on file to support the registration of a two percent diphacinone product. Without the results of acceptable acute toxicity studies, DPR cannot determine whether the precautionary statement currently on the product label adequately identifies acute toxicity hazards.

In the fall of 1998, registrants submitted several diphacinone acute toxicity studies. After reviewing the data submitted to support the two percent diphacinone product, DPR determined that an acceptable rabbit acute dermal toxicity study and a dermal irritation study were still needed. DPR required the results of those studies to be submitted by August 1, 1999. DPR reviewed the data submitted to support the one percent diphacinone product and determined that an acceptable rabbit acute dermal toxicity study was still needed. DPR required the registrant to submit an acceptable study by September 1, 1999.

MANEB -- 3 Products

DPR registers fungicides containing maneb to control diseases of fruits, vegetables, and field crops. DPR placed products containing maneb into reevaluation on August 11, 1997. Data on file with DPR and literature in the public domain indicate that products containing maneb have the potential to be human skin sensitizers.

Skin sensitization (allergic contact dermatitis) is an immunological reaction of skin to a substance. In humans, such reactions include severe itching, redness, swelling, inflamed spots, blisters, or a combination of these symptoms. In the assessment and evaluation of the toxic characteristics of a pesticide product, determination of the product=s potential to cause skin sensitization identifies potential hazards to humans repeatedly exposed to the pesticide.

DPR required registrants to indicate how they intended to mitigate the potential skin sensitization hazard. One registrant chose to amend the labels of two of its products to add a skin sensitization warning statement. The registrant withdrew the California registration of a third product. The second registrant also chose to amend the label of its product to add a dermal sensitization warning statement.

The labels of all pesticide products containing maneb now bear a dermal sensitization warning statement. Therefore, DPR concluded the reevaluation on May 4, 1999.

PROPETAMPHOS (Safrotin) -- 1 Product

DPR placed products containing propetamphos into reevaluation on March 22, 1990. Applicators use propetamphos indoors as an insecticide. DPR initiated the reevaluation based upon illnesses attributed to use of products containing propetamphos. In addition to the reports of illnesses, DPR was also concerned about the potential for overexposure of humans in contact with rooms treated with propetamphos.

In September 1990, DPR required the registrant to submit the following studies: (1) a dermal sensitization study, (2) an odor threshold study, (3) an indoor exposure study, and (4) a dermal penetration study. The registrant submitted the dermal sensitization study in January 1991. Rather than conduct an odor threshold study, the registrant conducted a sensory irritation study. The registrant submitted the results of the sensory irritation study in June 1993. The results of an indoor exposure study were submitted in April 1994. Rather than conduct a dermal absorption study, the registrant requested DPR use an assumption of 100 percent dermal absorption. In July 1998, DPR issued a notice identifying the definitive toxicity and exposure studies and critical endpoints and no effect levels for the propetamphos risk assessment. DPR's conduct of a risk assessment of propetamphos is scheduled for completion in 1999.


Pesticide applicators commonly use chlorpyrifos to control insect pests in and around the home. On May 17, 1985, the Department of Health Services (DHS) submitted a study entitled "An Assessment of the Hazard From Pesticide Absorption From Surfaces." DHS's assessment addresses the home-use of pesticides. DHS found that use of the products may pose an acute hazard due to inhalation, dermal absorption, or ingestion exposure. At the request of DHS, DPR placed products containing chlorpyrifos for general home use into reevaluation on June 27, 1985. On February 9, 1987, DPR requested indoor exposure information. In response to the reevaluation request, the basic manufacturer of chlorpyrifos submitted the results of indoor exposure studies. DPR expects to complete its risk assessment of chlorpyrifos in 1999.


DPR conducts preliminary investigations on products for which possible hazards have been identified by DPR or other state or county agencies. As a result of evaluation, the investigations may lead to formal reevaluation.


Blue Chip Germicidal Cleaner is labeled for use in hospitals to clean hard surfaces such as, floors, walls, woodwork, and equipment. In compliance with Food and Agricultural Code (FAC) section 12825.5, the registrant of Blue Chip Germicidal Cleaner submitted an adverse effects disclosure. The registrant submitted the results of an eye irritation and an inhalation study. The data indicate that the product is Toxicity Category II for acute inhalation hazard and Toxicity Category I for eye irritation. The product label does not adequately identify either toxicity hazard. Amendments to pesticide product labels must be approved by U.S. EPA before they can be accepted by DPR. The registrant submitted an amended label to U.S. EPA which is expected to be approved shortly.

CLETHODIM -- 4 Products

The pesticide active ingredient clethodim is used as a systemic postemergence herbicide to control annual and perennial grasses in broadleaf crops. In compliance with FAC section 12825.5, the basic manufacturer of the pesticide active ingredient clethodim submitted an adverse effects disclosure. DPR reviewed the submitted dermal sensitization study and based on the results of the study determined that clethodim should be considered to be a skin sensitizer. DPR informed the registrant of its review and asked the registrant how it intended to mitigate the dermal sensitization hazard. At the request of the registrant, DPR agreed to allow the registrant to run another dermal sensitization study. The results of the new dermal sensitization study were submitted October 29, 1998, and are under review by DPR. Along with the data, the registrant also submitted copies of its request to U.S. EPA to amend the labels of its clethodim products to add a dermal sensitization precautionary statement. Amendments to pesticide product labels must be approved by U.S. EPA before they can be accepted by DPR. U.S. EPA accepted the amended labels March 29, 1999. DPR is currently reviewing the amended labels.

GIBBERELLINS -- 20 Products

Gibberellins are plant growth regulators that are used to cause grape clusters to elongate, decrease fruit set, and increase grape size. On citrus, gibberellins delay aging of the rind and produce a more orderly harvesting pattern. During the review of two new gibberellic acid products, DPR found that the label use directions allowed application to various food commodities including grapes, citrus fruits, and sweet cherries. The current federal tolerance for gibberellic acid on those commodities is 0.15 parts per million. There is a federal exemption from the requirement to have a tolerance for gibberellins on oranges at application rates of less than 20 grams of active ingredient per acre. However, label directions for use on citrus allow applications at greater than 20 grams per acre. The registrant provided no residue data, nor an acceptable residue method, to show that gibberellin residues will be under the tolerance at the maximum labeled use rates. The registrant stated that they did not provide residue data because U.S. EPA planned to exempt gibberellins from the need for a tolerance on all commodities at any use rate.

On October 23, 1998, U.S. EPA issued a Federal Register Notice proposing to exempt from the requirement of a tolerance residues of gibberellins in or on all food commodities. U.S. EPA proposed to exempt gibberellins from the requirement of a tolerance because of their non-toxic mode of action, toxicity profile, and low application rates. On June 11, 1999, U.S. EPA finalized the exemption from tolerance for residues of gibberellins in or on all food commodities. As a result, residue data are no needed.

MALATHION -- 3 Products

In reviewing the acute toxicity data base for products containing malathion, DPR's Medical Toxicology Branch determined three products do not bear an appropriate signal word and precautionary statement. Data on file with DPR indicate products containing 57 percent malathion are toxicity Category II for acute dermal toxicity and primary eye irritation.

DPR considered placing the three products into reevaluation. However, in order to resolve DPR's concerns, registrants would have to amend the labels of their products. Since all label amendments must be approved by U.S. EPA prior to their acceptance by DPR, we informed U.S. EPA of our concerns. Initially, U.S. EPA expressed reluctance at amending the labels of individual malathion products and wanted to wait until all malathion products finished the reregistration process. However, recently U.S. EPA stated that if the registrants of the three malathion products voluntarily amended their product labels to change the signal word and precautionary statement U.S. EPA would accept the amended labels. On June 23, 1999, DPR sent letters to the registrants of the malathion products requiring them to inform DPR, within 60 days, of how they intended to mitigate DPR's concerns regarding acute toxicity hazards.

For further information, please contact Ms. Ann Prichard, Senior
Environmental Research Specialist, Pesticide Registration Branch, by
e-mail at ( or by telephone at (916) 324-3931.

original signed by Barry Cortez


Barry Cortez, Chief
Pesticide Registration Branch
(916) 445-4377


California Environmental Protection Agency