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Handling Hazardous Sealants
What you don’t know can hurt you!
A warning about careful removal.A case for encapsulation.
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Key learning points:
• Identify failures, causes, and resulting problems associated with hazardous materials in some sealants.
• Identify the installed sealant and determine procedures for safe handling and removal.
• Learn how to perform on- or off-site testing of the sealant and substrate.
• Determine the best repair and replacement protocol based on joint condition, application, substrate and movement considerations.
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Request of SWRI members
• Projects in progress or approaching/bidding for potential video
• Information about local requirements, i.e. plant physical science depts.- universities, schools, hospital corporations, etc.
• Cost/benefit analysis removal and disposal vs. encapsulation
• Purpose: for training video and an SWRI Technical Bulletin
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The what, where, when, who, then how
• Polysulfides – PCB fluids• Two-parts and to a limited extent, one-part- asbestos
• Transformer fluid, Capacitors, Light Ballasts • Paints, Coatings, Sealants,
• Lead painted sealants, or caulks
• Cities with a predominance of old metal curtainwall, i.e. New York, Chicago, Boston, Philadelphia
• Pool and Aqueduct Applications
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Small, inexpensive, qualitative test kits can be used to determine the presence of chlorine in suspect liquids. If shown to be positive, quantitative information is available through fluid sampling and subsequent, commercial analytical testing.
EPA regulations affecting the management, removal and disposal of PCB materials began to impact the UA in the early 1980’s.
During the 1970s, federal legislation mandated the elimination of PCBs from distribution in commerce. To minimize the potential for adverse health effects caused by PCBs and other substances, Congress passed the Toxic Substances Control Act (TSCA), which strictly regulates all aspects of PCB use.
PCB’s are a subset of the synthetic organic chemicals known as chlorinated hydrocarbons. Between 1926 and 1977, PCB-containing products were manufactured for applications demanding stable, fire-resistant, heat-transfer properties. The most extensive use of PCBs occurred in dielectric fluids. Such fluids typically have the following characteristics: heavy oil appearance, high boiling point, high chemical stability, high flash point, low electrical conductivity, and low water solubility. PCBs were also used as plasticizers and additives in lubricating and cutting fluids. PCB’s are clear to yellow colored oily liquids or solids. Overheated PCB material from a ruptured capacitor may be black in color. UA applications include electrical transformers, large high- and low-voltage capacitors and fluorescent lamp fixture ballasts.
Background
Monsanto, GE, Westinghouse
Polychlorinated Byphenyls (PCBs)
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MANUFACTURER'S TRADE NAMESPCB fluids are often known by the term askarel, which is a generic name for synthetic electrical insulating material. Askarelsgenerate only non-explosive gases or gaseous mixtures when decomposed by an electric arc. Commercial mixtures contain PCBs, chlorinated benzenesand contaminants, in a range of concentrations.Manufacturers have used a wide variety of trade names, including:
PYROCLORSAF-T-KUHLSAT-T-AMERICA
CHLOREXTOLCHLORPHENPHENOCLORKANECHORTHERMINOL
PYRANOLNO - FLAMOLSOLVOLINERTEENHYVOL
FENCLORELEMEXEUCARELDYKANOLDUCONAL
DKDICONALDIACLORAROCLORASBESTOL
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Application Categories: Closed, Partial, Open
• Open systems are applications where PCB’s are in direct contact with their surroundings and therefore may be transferred to the environment
• Plasticizers are the most common used in PVC, rubbers, but also paints (as a flame retardant), adhesives, sealants, coatings
• Be aware in renovation that entail interior work, ie mold, that adhesives for wall coverings may contain PCB’s. Also ceiling boards and tiles where used as a flame retardant.
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PCB Waste• Although now PCB use is now prohibited, many
activities exist that can generate PCB waste• Building demolition, sealant removal, electrical
(fluorescent) light ballast removal, etc. • Much that was disposed is in landfills and can be
released by volatization into the atmosphere and leaching into groundwater
• Best method is to incinerate• Consult resources listed at the end for approved
handlers and disposal sites.
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Sealant Industry History• A prior sealant of choice; best for underwater, chemical
spill containment, metal curtainwall, IGU production• From introduction in the ’60’s to 1978 polysulfides
contained PCB fluid• Formulation had extended life, better UV resistance,
resistance to hardening with age• Morton Thiokol had a formulator’s licensing program• Formulation called for a percentage of PCB fluid in the
formulation• Since their introduction until the asbestos ban, many 2
part formulations called for asbestos to be added during mixing as a binder/filler
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How to spot danger• Identify 2 parts by observing bubbles in the
sealant from air entrapment during mixing• Surface crazing, effect of weathering, but
generally good condition beneath• Sulfur smell• Signs of incompatibility; gummy or crystallization
appearance on curing at point of contact vs. typical silicone to urethane wet to dry contact
• Look for the fibers• Remember your protective equipment, gloves,
and dispose of properly
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Things to Avoid• Avoidance• Cut out and Recaulk,
asbestos & lead painted caulk w/o proper handling
• Cut out and Recaulk in PCB applications on assumption fluid will be gone
• Refer to mfr’s warranty disclaimer: discuss future disposal
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Quick TipsPCB laden sealants will have a strong sulfur
smell when cut out. Note, burn test. Avoid.
Search for a joint on the northeast façade
Handle with gloves, then dispose them
Bag the sealant for lab testing if suspect
Disposed sealants must be in properly labeled drums, properly disposed of
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Simple test for Chlorine (do not do this at home!)
Heat one end of a length of clean un-coated heavy copper wire (preferably 2 to 3 mm diameter) in a pale blue gas flame. If the wire is initially clean there will be no coloration of the flame until the copper reaches red heat when an orange hue will be imparted to it. Allow the wire to cool, somewhat below reheat, then dip it in the unknown chemical and again heat it. There may be an initial bright yellow and smoky flame – but as the copper nears reheat. The presence of chlorine will be indicated by a bright green coloration (the yellow should have disappeared at this stage), as it reacts with the copper to produce copper ions in the flame.
NOTE: When PCBs are decomposed at high temperatures, gases are produced which contain a high proportion of hydrogen chloride, a highly irritating and corrosive chemical. CONDUCT THIS TEST IN A WELL-VENTILATED PLACE.
The above test for chlorine is not infallible. However, it will usually suffice to distinguish between chlorinated hydrocarbons and non-toxic mineral, vegetable or silicone oils, greases or waxes.
If these screening tests are positive the material should be dealt with as if it is a PCB liquid, but the composition of the PCB liquid can only be determined by laboratory analysis. This can be carried out by various laboratories.
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Lab Test Procedure:
The details of the entire procedure for determining the PCB content of an insulating fluid are given in the ASTM D 4059 method and are only briefly mentioned here. A sample of the fluid to be analyzed is diluted with a suitable solvent and the resulting solution is treated to remove any substances that could interfere with the determination. A sample of the treated solution is then analyzed by gas chromatography utilizing an electron capture detector, which is very sensitive for chlorine containing species. The resulting chromatogram is compared against standard chromatograms for the various known Aroclors. This data then allows one to identify which Aroclor or mixture of Aroclors is present and to quantitate them. The results are usually reported in terms of parts per million (ppm) of each Aroclor present.
Expect a report noting percent concentration and recommendations. Suggest the owner hire an environmental consultant
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Exposure Levels
●Skin absorption is moderate, and contributes significantly to all symptoms of long-term exposure. Sensitized individuals may develop a rash after two days of exposure by contact or inhalation.
●PCBs may produce eye irritation. Levels of 10 mg/m3 are severely irritating.
●Inhalation may produce irritation to the nose, throat and lungs. Levels above 10 mg/m3* are reported to be unbearable. Inhalation may contribute significantly to all symptoms of long-term exposure.
●Ingestion contributes significantly to all symptoms of long-term exposure. There are no reported deaths of humans due to a single ingestion; however, experiments in animals suggest that ingestion of 6 to 10 fluid ounces would cause death to a healthy 150 pound adult.
●PCBs are readily absorbed into the body by all routes of exposure and may persist in tissues for years after exposure. Symptoms may be felt immediately, or they may be delayed for weeks or months, and may last for months.
●High levels of PCB vapor (1 to 10 mg/m3) may produce a burning feeling in the eyes, nose and face; lung and throat irritation; nausea; dizziness; and chemical acne.
Characteristics and Potential ExposuresPCBs are mixtures of chemicals that form clear to yellow, oily liquids, or mixtures that form white, crystalline (sand-like) solids and hard resins. They are used in insulation for electric cables and wires in the production of electric condensers, as additives for extreme pressure lubricants, and as a coating in foundry use.
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PCB Contamination Research Center -A PCB lawyer can help you fight back
PCBs have been used as dielectric fluid for capacitors and transformers, sealants, plastics, adhesives, hydraulic fluids, additives in pesticides, paints and lubricating and cutting oils. Heavy exposure to PCBs causes skin conditions such as chloracne and rashes, and can also cause cancer.
In this section you can learn more about PCBs, read updated news & warnings, and get answers to frequently asked questions. Then you can see if you qualify for a lawsuit, get a free case review, and do the research for free.
DON’T LET THIS BE YOU or ANYONEat your company!
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What to do? Buildings must be repaired to prevent further
structural, substrate and interior damage
717 Fifth Ave., NYC, Brisk Waterproofing
19Coping with wet applied sealant
ANSWER: Encapsulate vs. remove whenever possible.Option 1, wet applied bridge joint
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Option 2: Pre-Cured Silicone (or urethane,STP, SPUR )Extrusion
− Simply applied over the failed sealant joint− Much less costly and labor intensive than the conventional practice
of cutting out failed sealant and re-caulking− Eliminates potential damage to soft and sensitive substrates (i.e.
EIFS) during removal of failed sealant
ImmerSealadhesive
failed sealant
Pre-Cured
ImmerSeal
adhesive
failed sealant
Pre-Cured extrusion
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Notable Early Discovery Projects
• McKesson Plaza, San Francisco• New York Hilton and Towers• Newark Hilton• 1 Battery Park Plaza, NY• Pfizer World Headquarters, NY
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Pre-Cured
Provides advantages compared to wet seals including:
– Higher movement capability– Uniform factory controlled
cross-section– Less joint preparation– Better Appearance– Availability of different
surface finishes
Disadvantages– higher material cost– Need to order/work with sizes– Rippling- time of year installed
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I m m e r S e a l P r e fo r m e d S i l ic o n e J o in t S e a la n t
T r a d i t io n a l W e t A p p l ie dJ o in t S e a la n t
J o in t M o v e m e n t P lu s 2 5 %
J o in t M o v e m e n t M in u s 2 5 %
Pre-Cured
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Pre-Cured
Services:– Custom color matching– Special surface texturing– Custom design
• Custom width• Custom thickness• Custom shapes• Profiles with notches/bend-lines, allow for a variety of
installation configurations
– Special packaging
Notches
Installation Variations
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Notches
Installation Variations
− In order to apply in a three-dimensional configuration, notches can be extruded at almost any location across the width of the extrusion. These notches allow the product to be bent to the desired shape during installation. The green strength of the adhesive sealant will hold the extrusion in place until the sealant is cured - the shape is then permanent.
− Notched extrusions are manufactured using a continuous process and are rolled up flat in 100 ft increments, eliminating the risk of permanent deformation. Three-dimensional high consistency shapes cannot be rolled flat, but have to be folded into large packages in order to minimize distortion.
Three-Dimensional Shapes
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Remedial Applications
ImmerSealadhesive
failed sealant
ImmerSeal
adhesive
failed sealant
−Simply applied over the failed sealant joint− Much less costly and labor intensive than the conventional practice of
cutting out failed sealant and re-caulking− Eliminates potential damage to soft and sensitive substrates (i.e. EIFS)
during removal of failed sealant
Pre-Cured
Pre-Cured
Cut failed sealant at center point in EIFS
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adhesiveImmerSeal™
ImmerSealadhesive
ImmerSeal™
ImmerSeal™adhesive
Applied on the top of the substrate surface, bridging the joint. Often referred to as a “Bridge Seal, Band-Aid®, or Tape”.
Applied in a recessed joint configuration. This application looks more pleasing than the “Bridge Seal” application but requires a consistent width of the recessed joint.
Applied in a recessed concave joint application. The installation is quick and easy and looks great. Simply snaps into the opening. The concave configuration keeps the extrusion from bulging outward.
Pre-Cured in New Construction JointsPre-Cured
Pre-Cured
Pre-Cured
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Pre-Cured and Early Joint Movement
− Standard wet applied sealants areusually 1 part moisture cure systems
− Cure rate is highly dependent on sealant thickness
− Depending on the joint configuration and cure chemistry, a 90% cure can take up to 4weeks!
− The silicone adhesives used to install Pre-Cured are also moisture cure systems. However, since Pre-Cured is 100% Silicone, its water vapor transmission rate is very high and only a thin layer of adhesive has to cure.
−Hence, a 90% cure of the adhesive is reached within hours!
A building cannot be stopped from moving. Thermal expansion and contraction is a dailyoccurrence
− The cure time for the Pre-Cured adhesive is exceptionally rapid
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Usually produced in 1 mm or 2 mm thickness
Wet applied sealant is recommended to be applied at a thickness of 6 mm. This higher profile can be problematic for long term aesthetics. In the horizontal it creates a wider shelf promoting the collection of dust and pollutants.
Usually manufactured with a uniform profile
Application of wet sealant at a consistent width and thickness of 6 mm is difficult and time consuming.
Does not require a bond breaker tape. The adhesive sealant which bonds the Pre-Cured to the substrate is physically weaker and will tear within itself, under tensile stresses thus creating a neutral zone.
Wet applied sealants require the use of bond breaker tape to artificially create the proper joint configuration. Uniform application of wet sealant evenly centered over the bond breaker tape is difficult to master.
ImmerSeal
adhesive
substrate
ImmerSealadhesive
substrate
wet applied sealant
bond-breaker tapesubstrate
Pre-Cured Provides Advantages For Butt Joint Applications
Pre-Cured
Pre-Cured
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sealant-adhesive
bonding surfaces
masking tape
Figure 1: Application Examples
adhesive-sealant
Pre-Cured Sealant
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Pre-Cured Sealant Installation Guidelines
• Clean the substrate• Mask areas of high visibility• Apply adhesive to the
substrate• Place the Pre-Cured over the
area to be sealed • Press firmly into place• Trim, clean and tool
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Installation Apply Adhesive to the Substrate
• Apply a bead of sealant near the outside edges of the area to be sealed
• Sealant bead size should be 1/8”-1/4” depending on the uniformity of the substrate surface– Non-porous substrates (glass,
aluminum, etc.) will require less adhesive sealant
– Porous substrates (concrete, brick, stucco, etc.) will require more adhesive sealant
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InstallationPlace the Pre-Cured Extrusion Over the Area to Be Sealed
• Cut the material to the appropriate length
• Place the material uniformly spaced over the area to be sealed
• Material should be installed within 10 minutes of the adhesive sealant application
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InstallationPress Extrusion Firmly Into Place
Press the material firmly into place to ensure even wet-out of the sealant adhesive
– To achieve uniform appearance, a roller may be used on smooth surfaces.
– A flat object such as a piece of polystyrene insulation may be used on non-uniform surfaces
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InstallationTrim, Clean and Tool
• Trim extrusion if necessary
• Remove masking tape
• Tool or remove excess adhesive sealant before it cures
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Installation Considerations
• Adhesion of the adhesive sealant to the substrate should be tested prior to installation –follow Manufacturer’s guidelines
• Extrusion termination points should be sealed with a bead of adhesive sealant
• Vertical joints should overlap horizontal joints
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Arsenic and Old Lace: What Problems May we be creating for
the future, now• Mildew resistant sealants• If it kills bugs, what else does it effect?• Arsenic based biocides• Most common biocides no longer arsenic
based• Smaller issue is for sealants, but coatings,
grouts, PVC's?• Anti-microbial craze
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Infection Control or Greenwashing? Unintended Consequences of Overdesign (Part II)
Bruce Maine 07/01/06 LEED-certified design consultant Bruce Maine follows up his assessment of gypsum wallboard, ceiling tile, and paints with some tough questions about the health benefits and risks presented by antimicrobial cleaning agents.
...germs are real and constitute a serious threat -- especially in environments where infection control isn't just a casual incentive but absolutely necessary…The industry has adapted strategies from sophisticated technical enhancements, such as UV lights in supply air ducts, to more tested and fundamental hygienic imperatives like providing hand washing sinks in patient rooms. The building products industry has also responded to the challenges of infection control, but in a much different manner. As concern for the efficacy of the interior environment continues to grow, so does the pallet of products that are intended to combat mold, mildew, and biological contaminants.
The question that should be asked, however, is to what extent these product enhancements are truly beneficial, or if appropriate design is the better strategy to eliminate unwanted and dangerous contaminants in the interior environment.
Sanitizers, Biocides, and Antimicrobials
9-06 CSI Newsletter
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CautionsThe Centers for Disease Control (CDC), June 2000 draft of Public Health Action Plan to Combat Antimicrobial Resistance PDF)called for an evaluation of "the benefits and risks of incorporating antimicrobial disinfectants or antiseptic chemicals into consumer products (e.g., soap, toys, kitchen utensils, clothes, paints, plastics and film preservatives)." The NIOSH/EPA document, Building Air Quality: A Guide for Building Owners and Facility Managers, recommended that biocides, disinfectants, and sanitizers "be used with caution to ensure that occupant exposure is minimized." In the CDC's 2003 Guidelines for Environmental Infection Control in Health Care Facilities, the Construction Design and Function Considerations for Environmental Infection Control stress proactive design measures to achieve infection control attributes in building products in lieu of recommending products with pesticides to achieve those same results.
Sustainable design requires us to view our profession with a different perspective. It is no longer possible to walk away from a project without understanding the consequences or ramifications of our labor.
NOTE: that many/most antimicrobials added to sealant formulations only last a few years and have minimal if not questionable improvement overconventional formulations
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A Few References
• Construction Sealants and Adhesives, 2nd Ed., Panek and Cook, Wiley
• Sealants in Construction, Klosowski, Dekker• Polyurethane Sealants, Evans, Technomic• Status of High Rise Building Sealants in the
U.S., Panek, Bldg Sealants, O’Conner, ed, ASTM STP 1069
• The Chemicals Within Us, National Geographic, October 2006
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Resources
• Suppliers laboratories• Some charge, some do not want, or prefer not to
handle• Independent testing is best for addressing owner
and consultant concerns, particularly if there is potential or pending litigation
• Bob Haffner, Calcoast Analytical, P.O. Box 8702, Emeryville, CA 94662 (DL Labs Affiliate)
• Consult the SWRI Validation Lab List
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Credits (Thanks!)• Bob Haffner, Calcoast Analytical & Tom Sliva,
DL Labs• Peter Hagen & Jason Bakus, Sealex, Inc.• Jim Rogers, Brisk Waterproofing• Scott Haber, W&W Glass Products• Lee Straub, Gordon H. Smith Corp.• Steve Kraus, Skyline Windows• Greg Mayville, Dow Corning Corp.• Bob Kornfeld, LZA Technology• Sy Schulman (retired), Collyer-Sparks
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Handling Hazardous Sealants BXH-S60
QUESTIONS?
May National Associates, Inc.1700 Route 3 WestClifton, NJ 07013
Phone 1-800-641-0234Fax 1-973-473-4222www.bondaflex.com
This concludes the American Institute of Architects Continuing Education System Program
Doug Walker, VP Marketing, R&Ddougw@bondaflex.comCell 908-295-0957
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