6.0) FIRE and SMOKE: (page 3 of 6)

6.17.f) Molecule Formation of Ferrous Metals: Ferrous metals when impacted with hydrogen chloride or when affected by repeated hydrochloric acid will change the molecule formation of the metal over time.  This can result in the corrosion process to be irresolvable if not treated in a proper and timely fashion.

Ferrous metals have equilibrium of electrical current or EMF’s.  As an Example:  Iron (Fe) produces both positive (+) and negative (-) volts (Eº) which are called half-cells.  When the half-cells’ electrical currents are equal, corrosion should not form:

When ferrous metals are exposed to HCl and moisture, they break up into ions; hydrogen (H) has a positive charge (+) and chloride (Cl) has a negative charge (-).  When the HCl molecules form into ions, the hydrogen ion is lost to the water molecule, which moves between the chloride and the water acting as the acid and the base. This reaction of HCl ions causes an over voltage to one of the iron half-cells causing free energy and corrosion (rust) will form:

This free energy or excess EMF’s to the half-cell causes the right-angled molecule of the iron to align, which causes internal strain to the metal.

When the molecules of metal are aligned, the metal surface could require a vigorous agitation or pounding action before the metal would be completely neutralized of the HCl.  A vigorous pounding as produced from blasting, or 4 to 14 gallons per minute of water pressure per the SSPC would be needed to un-align the metals molecules back to their right angles.

Acids have varying strengths and reactions to metals, fabrics, etc.  An acid strength is based on the number of hydrogen ions that have transferred to the base.  Weak acids transfer a fraction of the ions of strong acids as shown in Table 6-D --- highlighting acid strengths in aqueous solution at room temperature.
 

Acid Strength in Aqueous Solution
At Room Temperature
Source: William Yobe & Associates
Table 6-D

6.17.g) Electrical Equipment and Wiring:  The National Electrical Code^®, NEC^® addresses soot, dirt, heat, chemical, gases, fumes and vapors in several Articles as listed below:

- "The principal cause of insulation failures are heat, moisture, and dirt.  Insulation can also fail due to chemical attack, mechanical damage, sunlight, and excess voltage stresses."  (NEC-HANDBOOK, Article 110-7)

- "Unless identified for use in the operating environment, no conductor or equipment shall be located in damp or wet locations; where exposed to gases, fumes, vapors, liquids, or other agents having a deteriorating effect on the conductor or equipment; or where exposed to excessive temperatures."  (NEC, Article 110-11)

- "Internal parts of electrical equipment, including busbar, wiring terminals, insulators, and other surfaces shall not be damaged or contaminated by foreign matter such as paint, plaster, cleaners, abrasives, or corrosive residues.  There shall be no damaged parts that may adversely affect safe operation or mechanical strength of the equipment such as parts that are broken; bent; cut; or deteriorated by corrosion, chemical action, or overheating."  (NEC, Article 110-12 (c).

Reprinted with permission from NFPA 70-1999, the National Electrical Code^®, Copyright^© 1998, National Fire Protection Association, Quincy, MA. 

This reprinted material is not the complete and official position of the National Fire Protection Association, on the referenced subject which is represented only by the standard in its entirety. National Electrical Code^® and NEC^® are registered trademarks of the National Fire Protection Association, Quincy, MA.

Electrical apparatus and equipment when mounted within rain tight or explosive proof housing should be protected from PIC's and should not require mitigation of their interior components.  Exposed NM cable (romex), open feeders, devices, appliance and equipment cords should be wiped clean.  While motors, panels, disconnect switches, terminal strips, circuit board, etc. not enclosed in rain tight or explosive proof housing should receive appropriate neutralizing in and out when affected with hydrogen chloride or hydrochloric acid.  The cleaning method, and to what level chlorides and sulfates should be reduced should be confirmed with the apparatus and/or equipment manufacturer.

Electrical wiring insulation could be constructed of plastics containing polyvinyl chlorides (PVC), which could be neutralized using a mild detergent and water.  All wiring insulation should inspected for charring and heat damage.  When in doubt about a wire or motors’ integrity, an infrared and/or insulation resistance test should be performed.  

Brushes, contactors, lugs, bugs, etc. when affected with hydrochloric acids should be cleaned with an approved cleaner.

Motors, when affected with hydrogen chloride should be electrically disconnected before cleaning, and should be cleaned using methods approved by the manufacturer.

Regulated compressed air could be used to remove loose soot deposits.  When using compressed air on electrical equipment, care should be taken not to drive or force soot and dirt particles into windings, insulation, bearings, under tape, lugs, etc.  

Insulation used on motor and transformer windings, etc. could contain synthetic fibers that could deteriorate when cleaned with some solvents, causing premature electrical failure per NEC, Article 110-11, FPN No. 2.  Moreover, before using solvents, the manufacturer should be consulted.

Motors and equipment bearings should be inspected for soot, smoke and corrosion, since bearings can fail prematurely due to heat, moisture, dirt, soot, rust and excessive (load) operating conditions.  Heat can also dissipate the lubrication on a bearing, allowing corrosive materials to cause rusting to the low alloy liners within a bearing housing, which are used to correct uneven rotation.  Bearing should be cleaned and lubricated as described in Section 7.30.a.

Equipment or apparatus when manufactured with ultrasonic welds should not be cleaned using ultrasonic methods unless pre-approved by the manufacturer.

Insulation coverings should be dried-out or replaced before re-energizing as described in Section 7.30.

The testing of electrical equipment and/or apparatus should be performed by or under the direct supervision of a competent person.

All electrical power should be disconnected before attempting to work on electrical equipment, apparatus, devices, wiring, etc. 

When electrical equipment and apparatus are wet or under high humidity attack, the procedures found in Sections 7.30 and 7.30.a should apply.

6.17.h) Electronic Equipment: Electronic equipment like electrical equipment is vulnerable to hydrogen chloride gases, hydrochloric acid, soot and smoke.

Electronic equipment such as computers, televisions, stereos, etc. have ventilating holes in their housing, which are an access for smoke soot and gases to the inner electrical and mechanical parts of the electronic equipment.  The outer housing of electronic equipment is generally constructed of plastics, or metal with a plastic coating and both are vulnerable to discoloration.

The repair, testing, cleaning, neutralizing or drying of electronic equipment should be performed using the manufacturers specifications, or Military Specification (Mil Spec) 28809A and 28809B as applicable should be used when manufacturers do not have specifications in-place.  While method of detergents, chemicals and/or mechanical actions such as; regulated air, ultrasonic, C0₂, soda ash or low-pressure washing is acceptable, when approved by the manufacturer.  Operation manuals and manufacturers should be consulted before disassembly begins, and technicians should refer to serial and model numbers when consulting manufacturers.  

Equipment manufactured with ultrasonic welds, integrated circuits or semiconductors should not be cleaned using ultrasonic methods unless pre-approved by the manufacturer.

Electrical wiring found in electronic equipment is generally heat resistant and vulnerable to acid and soot attack, and should be rinsed after cleaning with clean mineral free water and dried before reassemble.  The drying of electronic equipment should be performed in a regulated environment.

When neutralizing electronic equipment, the sodium chloride equivalent (SCE) should be reduced to levels determined by the electronic equipment manufacturer.  When the electronic manufacturer does not have SCE specifications in-place, the SCE should be reduced to 20 mcg/per square inch as determined by Military Specification (Mil-Spec) 28809A.

The repair, testing, cleaning, neutralizing or drying of electronics should be performed by or under the direct supervision of a competent person. 

When moisture or water affect electronic equipment, they should be disconnected at the power source.

Extracted from the Loss Recovery Guide with Standards (LRGS)
© Copyright 1998-2008 William Yobe

Find It Fast - With The ... LRGS - Navigational Index

 

6.18) Surface Testing:  The deposit of smoke, soot and gases can affect horizontal and vertical surfaces both structural and contents within a single room, and these deposits could be spotty.  Smoke, soot and gases deposits could be black, brown, gray, white or clear resulting in subjective opinions.  Subjective structural components, substrates and content items should be tested to determine if smoke, soot, gases or contaminates are present.  Before testing begins, technicians should determine the fuel source of the fire.  This would help in determining the methods and type of tests needed.  When the fuel source is acidic, the acidic (sulfate and chloride) levels of structural metal surfaces should be tested before and after mitigation or restoration procedures as described in Section 6.18.a.

6.18.a) Chloride Field Test: The use of a chloride ion field test is an accurate method when determining acidic levels on structural metals in the field.  However, field tests when positive, should be quantified using an ion chromatography test.

Chloride field testing kits (Chlor*Test) can be purchased from CHLOR*RID International or from KTA-Tator.

6.18.b) Soot Testing: When soot deposits in rooms and surfaces appear to be minor, spotty or subjective, they should be tested using a cellulose dry sponge, wipe or swab sample.  When soot conditions are undetectable to the naked eye, samples from the surface or the surface itself should be examined with the aid of a microscope. 

When soot conditions are subjective or not visible, testing maybe necessary for the following reasons:

   - As hot smoke and soot from a burning fire meet cool air within
     an adjoining room, an atmospheric reaction of wavelengths
     sends soot and smoke deposits throughout a structure. 
     As the smoke and soot cools, their effects can be varying
     on  structural surfaces and content items.  

   - Soot is attracted to varying surfaces due to a temperature
     differential.  Cool surfaces will attract soot residues before
     warm surfaces.  During winter months, soot deposits could
     be heavier on exterior walls.  During summers months, the
     location of heavy soot deposits could vary based on the
     time the fire started and the temperature of the building
     envelope and the placement of contents.  Cabinet
     and furniture interiors, when cooler than the air
     within a structure could attract hot soot deposits.

   - Atmospheric pressure caused from heated gases can force
     soot and smoke within confined areas of a structure and
     content items as well as affect the underside of content items

   - Smoke and soot deposits could be black, brown, gray, white
     or clear.

6.19) Protein Fires: Misty soot, as produced from a protein fire are attracted to and can infiltrate cool nooks, crannies, as well as deposit within and beneath content items.  The micro-size of protein soot could result in property owners, adjusters and technicians to attempt a quick cleaning process, which could fail.

The decomposition of living organisms found in animal fats is exotoxin bacteria, and can be toxic and emit foul decaying odors.  Moreover, when left on painted surfaces can turn to a beige-pink color in a short time, possibly requiring a full restoration of cleaning, sealing and painting. 

Surfaces with light soot deposits should be thoroughly cleaned using a mild detergent, while heavy concentrated areas could require strong degreasers.  Careful detail should be addressed to the interior and underside of contents, building components, as well as nooks and crannies. 

Food service and personal hygiene surfaces should receive an application of an approved disinfectant after cleaning. Disinfectants should be allowed adequate time to react and surfaces should be rinsed with clean mineral free water after disinfectants have had adequate time to react. 

Detergent aromas could cover up protein odors only to have them reappear.  When protein odors reappear, the testing methods in Section 6.19.a should apply.

Affected upholstery, carpets and clothing should be cleaned, and disinfected when necessary. 

Protein fire mitigation is not a one-stop process, but a trial and error process and could require several processes.  Property owners and adjusters should be made aware of all steps and procedures before and during the mitigating process.
 

6.19.a) Protein Fire Testing: Protein fires are from living organisms such as poultry and beef and could produce a clear invisible misty soot that could be unnoticeable to the naked eye. 

Protein soot deposits can be tested by extracting a surface sample using a non-alcohol wipe or swab and examined using a microscope. 

When baseboards and casing have a stained finish, and a small gap is present, the baseboard/casing should be loosened and samples taken from the backside of the baseboard/casing and tested. 

When odors persist after cleaning, certain areas or building components should be encapsulated within plastic sheeting for 24 to 48 hours, which can help narrow down the affected (odor) areas.

The testing and evaluation of protein samples should be performed by or under the supervision of a competent person.

6.20) Mitigation and Restoration Equipment: The loss type, surface types and post-conditions would determine the types and quantity of equipment needed to mitigate or neutralize a loss site. See Section 4.0 for a brief listing of mitigation equipment.

6.20.a) Mitigation Equipment Inspection: Equipment left on site, in an operable state for a considerable amount of time (overnight) should be inspected at minimum, once in a 24-hour period.

This should include gas-powered equipment (generators), airmovers, dehumidifiers, ozone generators, ULV foggers, injection dryers, air scrubbers, etc.

6.21) Structural Surfaces: Structures can contain varying surfaces:

    - Walls and ceilings could be painted drywall or plaster. 
      Paneling could have a wood or photo finish.  Tile
      could be ceramic, metal or plastic.
    - Wall coverings could be paper, vinyl or cloth. Casings
      and baseboard could be painted or stained, soft or
      hardwood, or pre-finished vinyl.
    - Doors and windows could be vinyl, painted or stained
      wood, aluminum or steel.
    - Kitchen and bath counter tops could be constructed
      using ceramic tile, plastic laminate or hard surface materials.
    - Kitchen and bath fixtures could have chrome, nickel or
      gold plate, porcelain, fiberglass or acrylic finish.
    - Cabinetry could be constructed from veneer  plywood,
      hardwood (stained or painted) or powder coated metal.
    - Floor surfaces could be sheet or tile (VCT) vinyl, hard
      or soft wood, glazed or non-glazed tile, marble or carpet.
    - Carpets could be constructed from natural wool, cotton,
      silk, jute, or of synthetic nylons: 2^nd, 3^rd, 4^th, 5^th
      generation, polyester, olefin, acrylic or rayon.

Based on the varying surfaces listed above, contractors should stock a full range of chemicals and cleaning agents with respect to their surface reaction, strengths, compounds and make-up range as described in Section 4.7.

Surfaces should be tested for reaction and colorfast before applying chemicals.
 

 

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