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FDA Collection and Analysis of Food for Perchlorate - High Priority - DFP # 04 - 11


December 23, 2003
Consumer Safety Officer, Division of Field Programs
Office of Compliance, CFSAN
Thru Chief, Compliance Programs Branch (HFS-636) ____
Collection and Analysis of Food for Perchlorate - High Priority
DFP Assignment # 04 - 11 ORA Concurrence # 2004121101
FACTS # 494779
FOI Version
[Addressees Redacted]


Perchlorate is both a naturally occurring and man-made chemical. Naturally occurring perchlorate, for example, is found in nitrate fertilizer deposits from Chile. Most of the perchlorate manufactured in the U.S. is used as the primary ingredient of solid rocket propellant. Wastes from the manufacture and improper disposal of perchlorate-containing chemicals are increasingly being discovered in soil and water.

Perchlorate at high doses can interfere with iodide uptake into the thyroid gland, disrupting its functions. In adults, the thyroid helps to regulate metabolism. In children, the thyroid plays a major role in proper development in addition to metabolism. Impairment of thyroid function in expectant mothers may impact the fetus and newborn and result in effects including delayed development and decreased learning capability. Chronic lowering of thyroid hormones due to high perchlorate exposure may also result in thyroid gland tumors.

The FDA is investigating the ways that plants take up perchlorate. Perchlorate might get into plants when they are irrigated with perchlorate-containing water or when plants are grown in soil that has been previously exposed to perchlorate-containing water or fertilizer. Perchlorate in water used for food processing might also be a source of contamination in finished food products. Only certain agricultural areas appear to have perchlorate in water sources or the soil, and only these areas would be expected to potentially have perchlorate in crops.

The FDA needs information on the presence and levels of perchlorate in foods that are expected to contain perchlorate. The FDA has developed its own method for measuring perchlorate in different foods and is planning to collect foods nationwide for perchlorate analysis. Collection and analysis will focus on foods that are suspected to contain perchlorate (e.g., lettuce), and on items from regions where water sources are believed to be contaminated with perchlorate.


  1. To collect a variety of food samples, such as lettuce and bottled drinking water, for perchlorate analysis
  2. To generate information on the incidence and levels of perchlorate contamination in selected food items. The data will be used to determine the need for future monitoring and/or enforcement strategies.

Investigational Approach

Sample collections are planned for two phases. A total of 500 samples are planned overall. Product selection will be based on the availability of an appropriate method for measuring perchlorate in each commodity. Method testing is presently being conducted at CFSAN.

The first phase of this assignment calls for collection and analysis of a total of 150 lettuce samples (i.e., iceberg, romaine, and green/red leaf lettuce) and 50 bottled drinking water samples. Samples will be analyzed at [Laboratory Name Redacted].

For the second phase of this assignment, CFSAN's Office of Plant and Dairy Foods and Beverages will develop a list of additional 300 foods for collection and analysis as appropriate sample preparation methods for measuring perchlorate in these foods become available. The CFSAN Assignment Contact will then transmit sample requests (sample collection schedule) to the districts in a separate addendum to this assignment. It is anticipated that the second phase of collections will be issued by the end of the second quarter.

Sample Collection

  1. Lettuce:

    Attachment A contains a list of lettuce samples for immediate collection in the first phase. The collecting districts, products, seasonality and the number of samples are included in the Attachment.

    Lettuce harvested in December through February is designated as winter lettuce and lettuce that is harvested in March through May is designated as spring lettuce.

    • [Instructions to Districts Redacted]
    • Collect the commodities of local origin and record in the C/R the name of the growing areas (e.g. counties and cities). The name and location of the grower, and water source, is required for all lettuce collections.
    • Collect the samples of lettuce at growers or packing sheds.
    • Do not collect samples at retail establishments.
    • Do not collect domestic import samples; Products must be of U.S. origin.
    • Collect samples as surveillance samples.
    • Lettuce should be shipped intact. [Analyzing Laboratory Name Redacted] will prepare the lettuce for storage/analysis as appropriate.
  2. Bottled Water:

    The Attachment B contains a list of bottled water samples for immediate collection in the first phase.

    • Collect bottled drinking water samples at retail establishments. Collect bottled water samples with the source water from municipal water systems (e.g., labeled as "drinking water" or "purified water") or from groundwater (e.g., labeled as "spring water") (21 CFR 165.110) FROM the areas identified on Attachment B.
    • All bottled water samples collected must declare the source (e.g., the location of a municipal water system or the location of a spring) or if not, the investigator must determine the source to be considered an appropriate sample.
    • Collect samples and record the location of the source water in the C/R.

Sample Size

For lettuce, follow the IOM Sample Schedule Chart 3 for minimum sample sizes (the number of subs varies by the size of lot).

For bottled water, sub size will be 1 retail unit (minimum 1 pt or 16 fl oz). When the retail container is less than 16 ozs, collect subsequent units to results in at least 1 pint. Refer to IOM subchapter 452 for sample handling details.

Sample Shipment

Refer to IOM subchapter 454 for sample shipment instructions.

Lettuce: Mark the outside of each parcel PERISHABLE. Ship samples packed in ice by overnight service. Refer to IOM 452.6 for instructions on shipping refrigerated samples.

Bottled water: Samples may be shipped as non-perishable items.

Do not ship lettuce samples on Fridays.

Ship both lettuce and bottled water samples to: [Analyzing Laboratory Address Redacted]

Sample Analysis

Sample Storage:

Sample storage will only be necessary if [Analyzing Laboratory Name Redacted] does not have their equipment up and running in time for this assignment.

  • Lettuce: Remove outermost leaves of head, similar to the actions typically taken by a consumer prior to consumption. Chop lettuce in a grinder or food processor and store in glass jars. Composite the sub-samples to represent a sample for analysis. Hold samples at -20°C, bring to room temperature before perchlorate analysis.
  • Bottled Water: No preparation is required. Bottled water samples should be stored at room temperature.

All samples are to be analyzed for perchlorate.

Determine perchlorate in lettuce and bottled water by using the following method (a copy of the method will be provided electronically to the participating laboratory): Draft "Rapid Determination of Perchlorate Anion in Lettuce and in Bottled Water by HPLC/MS/MS".

Please contact Alex Krynitsky at (301) 436-2098 (Updated contact number: (240) 402-2098), should you have questions regarding the method.

The limit of quantitation (LOQ) for lettuce is 1 ppb (µg/Kg) perchlorate and that for bottled water is 0.5 ppb (µg/L) perchlorate.

Sample Disposition:

Upon completion of analysis, the lab should maintain all reserve samples (both positive and negative) until advised by CFSAN of disposition. Selected samples may be requested to be sent to CFSAN. Please contact Alex Krynsitsky, DPIC, CFSAN, for disposition guidance.

Regulatory/ Administrative Follow-up

No regulatory follow-up is anticipated. Samples are being gathered to increase FDA's understanding of the presence, levels, and public health impact of perchlorate. Samples with unusually high levels of perchlorate will be assessed on a case-by-case basis.

Hard Copy Reporting / Resources

  1. Data Reporting:
    • Report all analytical results including blanks, reference materials and recoveries into the FACTS Data Reporting System using the PAC: 04F800
    • Report analytical results into FACTS using PAF: PES
    • Method Code: 998
    • In the Remarks file of the Method Applied Screen, please enter: CFSAN HPLC/MS/MS Method, draft 1.0
    • Product Codes:
      1. a) Iceberg lettuce24T [] [] 31
      2. b) Romaine lettuce24T [] [] 32
      3. c) Leaf lettuce24T [] [] 32
      4. d) Bottled water29W [] [] 01
  2. Resources:

    Resources are to be obtained from the "Field Assignments for Chemical Contaminants" 04F800 (CFSAN Initiated Field Assignments, FY 04).

Summary/ Evaluation

The Office of Plant and Dairy Foods and Beverages will prepare a summary and evaluation of the findings within 60 days of the completion of this assignment.

Start/ Completion Dates:

  • Sample Collections

    Begin: upon receipt
    End: Bottled water- 45 days
    Lettuce- February 27, 2004 (winter lettuce)
    May 31, 2004 (spring lettuce)

  • Sample Analysis

    Begin: upon receipt
    End: July 15, 2004


CFSAN Assignment Contact:

  1. Kaniz Shireen, CFSAN, Office of Compliance, Division of Field Programs Compliance Programs Branch, HFS-636, (301) 436-2775 (Updated contact number: (240) 402-2775) Email:

CFSAN Scientific (Survey Information) Contacts:

  1. Jennifer Burnham, CFSAN, Office of Plant and Dairy Foods and Beverages, Division of Plant Product Safety, Regulatory Policy Branch, HFS-306, (301) 436-2030 (Updated contact number: (240) 402-2030) Email:
  2. Henry Kim, CFSAN, CFSAN, Office of Plant and Dairy Foods and Beverages, Division of Plant Product Safety, Regulatory Policy Branch, HFS-306, (301) 436-2023 (Updated contact number: (240) 402-2023) Email:

CFSAN Scientific (Chemical Analysis) Contact:

  1. Alex Krynitsky, CFSAN, Office of Plant and Dairy Foods and Beverages, Division of Pesticides and Industrial Chemicals, HFS-336, (301) 436-2098 (Updated contact number: (240) 402-2098) Email:

ORA Scientific Contact:

  1. Charles Parfitt, ORO/Division of Field Science, HFC-141, Phone: (301) 827-1033 Email:


This assignment has high priority and to be implemented upon receipt.


Attachment A: [Attachment Redacted]

Attachment B: [Attachment Redacted]

Kaniz Shireen 

cc:[cc List Redacted]

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