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Evaluation of Wildland Fire Chemicals
Standard Test Procedures (revised 5/30/2007)

STP 2.2—Lateral Ignition and Flame Spread (LIFT)

Summary:

The lateral ignition and flame spread test (LIFT) can be used to as a measure of the ability of a product to inhibit the ignition of the substrate to which it is applied. The substrate, in a vertical orientation, is exposed to a known radiant heat source and the time to ignition measured.

The LIFT test as described below is required as a portion of the evaluation of wildland firefighting foams (FS Specification 5100-307a) and water enhancers (FS Specification 5100-306a).

Standard Conditions:

  • Radiant Heat—40 kW/m2
  • Piloted ignition; pilot flame in vertical position
  • Substrate: T1-11 siding, free of grooves
  • Vertical orientation of radiant panel and substrate
  • Stack of 3 pieces of siding, only top board is weighed and measured
  • Top (test) board with rough side exposed
  • Grain in horizontal direction; milled micro-grooves are vertical
  • Test boards are wedged in sample pan

Equipment Set-Up and Calibration:

  1. Step One
    1. Start the radiant heat panel and allow the heat flux to stabilize.
    2. Start and adjust the pilot ignition flame, located in front of the sample container where the radiant panel is closest.

  2. Step Two
    1. Set up a video camera with a clear view of the test piece during exposure to the radiant panel.
    2. Have adequate video tape and backup batteries for the cameras.
    3. Record all tests on video.
    4. Record all product information, test information, and measured data on the standard data sheet.
    5. Record data on the radiant panel performance on the system computer and obtain copies of all records.

  3. Step Three
    1. Verify conditions by running a test on an untreated board.
    2. Check the calibration by performing a control test on an untreated board at the beginning of each day and after lunch.
    3. Additional calibrations should be performed throughout the test series and any time that repeat tests have significant differences in results.

Substrate Preparation:

  1. Step One
    1. Have enough siding from a single source to complete the test series.
    2. Condition all test pieces before use. Temp: 70 °F ± 5 °F; RH: 50 % ± 5 %; Duration: at least 30 days after cutting.
    3. Number each test board (the top piece in a stack) on the back (smooth) side with a permanent marker.

  2. Step Two
    1. Weigh each test piece and record the initial weight.
    2. Using an electronic moisture meter, determine the moisture content on the smooth side of each test piece. Take three measurements, average, and record the moisture content. If there is a choice, select the setting for Douglas fir.

  3. Step Three
    1. Wedge the sample box in the holder using metal wedges (10d, 3 inch hard cut masonry nails).
    2. Place three pieces of T1-11 in the sample box so that the micro-grooves of the top piece are perpendicular to the length of the sample holder.
    3. When the sample holder is in place in the LIFT apparatus the micro-grooves should be in a vertical orientation. This will place the primary groove of the tongue and groove siding in a horizontal orientation.
    4. Use metal wedges (6d, 2 inch hard cut masonry nails) to ensure that the T1-11 pieces are held firmly in place.

  4. Step Four
    1. Pieces of T1-11 that have grooves from the tongue and groove finish should be bottom (elevator) pieces. These can be used over and over again.
    2. The middle piece of T1-11 can also be used many times but should be allowed to dry between uses.

Fire Chemical Preparation:

Prepare all test products with room temperature, deionized water as some products are sensitive to water hardness and temperature. Mix ratios will be specified for each product based on product requirements, manufacturers’ recommendations and submission information.

Standard Chemical (Water):

Weigh 250-gram samples of deionized water into beakers and allow to warm to room temperature.

Foam Procedure:

The foam is generated using a standard household blender (Waring Model 18BL93).

  1. Weigh 250 grams of room temperature, deionized water into beakers.
  2. Pour water into blender container.
  3. Inject foam concentrate into water with a hypodermic syringe just before mixing/blending.
    1. 0.1% foam solution = 0.25 ml of foam concentrate in 250 ml of water
    2. 0.4% foam solution = 1.0 ml of foam concentrate in 250 ml of water
    3. 1.0% foam solution = 2.5 ml of foam concentrate in 250 ml of water
  4. Blend the foam solution for 1 minute at high speed unless otherwise specified.
  5. Quickly note volume and character of foam.
  6. Pour the mixture into the sample box containing the T1-11.
  7. If all of the test product cannot be contained in the sample box, estimate the volume applied.

Water Enhancer (dry concentrate) Procedure:

Unless otherwise noted the enhanced water mixtures shall be prepared using a wand-style stirrer on low speed.

  1. Weigh 250-gram samples of room temperature, deionized water into beakers.
  2. Pour water into a 1-quart, disposable container.
  3. Sift dry concentrate into 250 mL of water.
    1. 0.5% water enhancer = 1.25 grams of concentrate in 250 ml of water
    2. 1.0% water enhancer = 2.5 grams of concentrate in 250 ml of water
    3. 2.0% water enhancer = 5.0 grams of concentrate in 250 ml of water
    4. 3.0% water enhancer = 7.5 grams of concentrate in 250 ml of water
  4. Stir the mixture for 10 seconds.
  5. Transfer (pour/scrape) the mixture into the sample box containing the T1-11.
  6. Allow 60 seconds total development time from the beginning of mixing.

Water Enhancer (wet concentrate) Procedure:

Unless otherwise noted the enhanced water mixtures shall be prepared using a wand-style stirrer on low speed.

  1. Pour water into a 1-quart, disposable container.
  2. Inject wet concentrate into 250 mL of water.
    1. 0.5% water enhancer = 1.25 grams of concentrate in 250 ml of water
    2. 1.0% water enhancer = 2.5 grams of concentrate in 250 ml of water
    3. 2.0% water enhancer = 5.0 grams of concentrate in 250 ml of water
    4. 3.0% water enhancer = 7.5 grams of concentrate in 250 ml of water
  3. Stir the mixture for 10 seconds.
  4. Transfer (pour/scrape) the mixture into the sample holder containing the T1-11.
  5. Allow 60 seconds total development time from the beginning of mixing.

Application of Test Product:

  1. Step One
    1. Place a piece of board or shim under the handle end of the sample holder in the hood to level the pan.
    2. Transfer the prepared product to the T1-11 as noted above for the appropriate product type.


  2. Step Two
    1. Wait the appropriate length of time, 0-minutes or 5-minutes soak for foams or 50 seconds for enhanced water mixtures.
    2. Tip the sample holder to vertical, bringing the left side to the top.
    3. Allow the sample to drain for 10 seconds.

Expose Sample to Radiant Heat:

  1. Remove the heat shield about 30 seconds prior to inserting the test holder into the exposure apparatus.
  2. Return the sample holder to the horizontal position and carry it to the exposure apparatus.
  3. Tip the sample holder to vertical, bringing the right side to the top, and insert the holder into the exposure apparatus.
  4. Record the time from exposure, to radiant panel, to ignition.
  5. If foam treated substrate does not ignite after 10 minutes of exposure, end the test and note “no ignition” on the data sheet.
  6. Step Six
    1. If water enhancer treated substrate does not ignite after 30 minutes of exposure, end the test and note “no ignition” on the data sheet.
    2. If flash or transient ignitions occur, note the time and frequency. If the flash continues for 30 seconds or if intermittent flashing continues for 30 seconds, sample is considered to have ignited.

Remove Sample from Radiant Heat:

  1. Remove the assembly from the exposure apparatus.
  2. Place in the hood in a horizontal position.
  3. Allow the assembly to cool in the hood until it can be handled comfortably.
  4. Verify the identity of the test board, if possible.

Typical Exposure Times:

  • Untreated substrate ignites in about 1 minute.
  • Water treated substrate ignites in 2 to 3 minutes.
  • Foam treated substrate ignites in 2 to 8 minutes, depending on the concentration and pre-exposure soak time.
  • Water enhancer treated substrate ignitions are much more variable, taking from 5 to 60 minutes.

References:

American Society for Testing and Materials. Standard Test Method for Determining Material Ignition and Flame Spread properties; E1321-1997(02)

Underwriters Laboratories Inc. Project Reports to USDA Forest Service; 98NK32277, 99NK35219, 01NK12843, 03NK13445, 04NK16188, and 06CA42655.


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