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For Immediate Release: August 26, 2005                                      
NR05 -17


HONOLULU – The Hawaii Department of Agriculture (HDOA) reminds residents, particularly on the Big Island, that there are specific directions that must be followed when using hydrated lime to control coqui frog infestations.

HDOA has received several reports that some residents are illegally applying the dust form of the chemical, a practice that is hazardous to humans and animals.  The dust form is only allowed for agricultural operations, which can restrict access to the treated area for at least 48 hours after treatment.  Residents are only allowed to use a three percent solution in a liquid form to spray on foliage or to drench the soil.

There has also been a report that dangerous misinformation has been posted anonymously in Pahoa that promote the use of leaf blowers to shoot hydrated lime dust across a wide area – a practice that is not only extremely dangerous, but illegal.

"We cannot emphasize enough the proper use of hydrated lime," said  Sandra Lee Kunimoto, Chairperson of the Hawaii Board of Agriculture.  “If misused, this chemical may cause irreversible eye damage and skin burns and is harmful if swallowed or absorbed through the skin and may be fatal if inhaled.”

"The Pesticides Branch has made it a priority to investigate reported misuse of hydrated lime," said Robert Boesch, manager of HDOA's Pesticides Branch.  "All pesticide dealers are also required by law to provide the label instructions to all customers purchasing the product for coqui control.”

HDOA's Pesticides Branch has the enforcement authority for both state and EPA laws.  Fines for violations of state and federal Environmental Protection Agency (EPA) rules for hydrated lime range between $1,000 to $5,000 per offense.  Suspected improper use of a pesticide should be reported to HDOA at:

Oahu - 973-9401
Big Island - 974-4140
Maui County - 873-3555
Kauai - 274-3069

Questions regarding the proper use of all pesticides may also be directed to those phone numbers.  Label instructions and forms are available on the HDOA website at:

On April 26, 2005, the EPA approved an emergency exemption requested by HDOA to allow the use of hydrated lime, also known as calcium hydroxide (CA(OH)2), to control coqui and greenhouse frog infestations in Hawaii. 

In granting the exemption, EPA requires that HDOA create a product label detailing the conditions under which hydrated lime may be used, which include the following:

  • Agricultural establishments are allowed to use the dust form of hydrated lime and worker entry into treated areas must be restricted for 48 hours after treatment.
  • Residential, commercial or public uses must be sprayed in a solution form.
  • Must not be applied to food crops;
  • Applicators must be wear protective clothing, chemical-resistant gloves and protective eyewear and approved respirators;
  • Include a precautionary statement that it is harmful if swallowed;
  • Must not be used in areas that were recently treated with ammonium-containing fertilizers, which may react with the lime and release ammonia.
  • Must not be applied to areas where children play or congregate;
  • Must not be applied to trees to avoid the potential for subsequent dripping of the chemical on people or property, such as automobiles;
  • For non-agricultural uses, such as around homes, persons other than the applicator are prohibited from entering the treated area until the spray has dried.

The Pesticides Branch held statewide workshops on proper use of hydrated lime in May and June. 


For more information, contact:

Janelle Saneishi
Public Information Officer
Hawaii Department of Agriculture
Phone: (808) 973-9560
To E-mail, click here