InspectAPedia ^®

This page illustrates and describes the fire resistant properties of cellulose building insulation materials. This document assists building buyers, owners or inspectors who need to identify building insulation materials and also people who need to recognize both asbestos materials (or probable-asbestos) in buildings as well as materials unlikely to contain asbestos - all by simple visual inspection.

In these articles we provide photographs and descriptive text various kinds of building insulation along with description of the characteristics of each material.

© Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

What is the Fire Resistance of Fire-Retardant Treated Cellulose Building Insulation?

Anyone looking closely at cellulose insulation can often see recognizable bits of newsprint in this chopped fibrous gray insulating material. Walking through a major home improvement center recently we picked up some loose fill cellulose insulation that fell out of a package of new cellulose insulation being purchased by a client. Our photos (above) show what it looked like when we put a little of this insulation on a ceramic dish in the sink in our forensic lab.

We were curious to know how fire resistant this random sample of new cellulose insulation would be in response to a very simple test. DO NOT TRY THIS IN YOUR HOME - you could start a fire.

Using an ordinary butane cigarette lighter and in safe lab conditions over a sink with water and fire extinguishers at ready (Photo above left) we heated the cellulose insulation for 60 seconds in direct flame. The temperature to which we exposed our cellulose insulation sample was perhaps hotter than the insulation might experience if it were in contact with a light bulb, but possibly no hotter than if it were in contact with shorting electrical wiring or an overheating aluminum branch wiring circuit connection.

There was a very brief tiny flame as a piece of plastic-coated newsprint in the insulation caught fire. The plastic on this newsprint probably resisted treatment by the fire retardant chemical and that fragment burned easily - and momentarily. Other than that small fragment, the insulation charred, smoked, but would not support combustion.

Cellulose building insulation manufacturers should avoid accepting plastic or water-resistant coated papers into their insulation manufacturing process, or at least be sure that water resistant paper is present only at such trivial quantities (as indeed it was in our test sample) that the cellulose insulation will not support combustion after treatment.

In sum, our amateur "fire test" demonstrated that our sample of new cellulose insulation would not support combustion. (Photo above right). But take a look at NAIMA's findings just below.

NAIMA's Fire Resistance Testing of Cellulose Insulation

Note that according to the North American Insulation Manufacturers' Association, the chemical treatment of cellulose insulation does not make cellulose insulation "non-combustible" nor does it prevent smoldering type ignition of the material. Cellulose insulation is tested for fire resistance using ASTM C-739.

It has also long been our opinion that the chemical retardant treatment, however effective it may be, may deteriorate over time or especially if the insulation is exposed to water - say from a roof or wall leak. NAIMA has a similar view.

In sum according to NAIMA "fire retardant treated cellulose insulation" is not necessarily completely fireproof.

But then, a chief competitor of cellulose insulation, fiberglass insulation products are also not exactly fireproof - the kraft paper to which lots of fiberglass insulation is affixed to ease installation (and provide somewhat of a vapor retarder), for example can be set afire and it is possible that some of the binder resins may support combustion.

ASTM C-665 is the test standard for fire resistance of mineral fiber batts and rolls, and ASTM C-764 is the fire test standard for loose fill mineral insulation.

In industry speak, fiberglass is considered a mineral fiber along with rock wool or mineral wool insulations.

Manufacturers of Cellulose Insulation

Some of the cellulose manufacturers registered by NIST include

• National Cellulose Corp.,
• U.S. Insulation Sales Corp.,
• Pal-O-Pak Insulation Company (aka National Cooperatives, Inc.),
• United Materials Corporation, and
• Insul-Wool Insulation Corporation.

Share this Article      

...

Technical Reviewers & References

Search InspectAPedia

• Daniel Friedman - principal author/editor of the InspectAPedia^® Website
• InspectAPedia Bookstore lists recommended books, organized by topic & available for purchase. Most of our articles also include a list of recommended books for the specific article topic as well as other references, and information sources.
• Critique, contributions wanted: Contact Us to suggest corrections or additions to articles at this website, and if you wish, to receive online listing and credit as a contributor. Particular thanks are due to the many experts and also consumers who read and critique technical articles at InspectAPedia.com.
• Additional technical contributors & reference sources for this article are listed below.

Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

ASBESTOS IDENTIFICATION IN BUILDINGS
INSULATION INSPECTION & IMPROVEMENT
Insulation Material Identification Guide
  Asbestos Identification in Buildings
  Asbestos Pipe Insulation
  Asbestos-Free Insulation Materials
  Balsam Wool Batt Insulation
  Cotton Insulating Batts
  Cellulose loose fill insulation
    Cellulose Insulation Identification
    Cellulose Insulation Inspection
    Cellulose Insulation R-Values
    Cellulose Insulation Mold Resistance
    Cellulose Insulation Fire Resistance
  Concrete insulation, light-weight
  Fiberglass Insulation
  Foam Board Insulation
  Foam Insulation Types - Visual Id
  Homasote & Other Insulating Board
  Icynene Foam Spray Insulation
  Insects & Foam Insulation
  Mineral Wool - Rock Wool Insulation
  Mold in Fiberglass Insulation
  Mold in Foam Insulation
  Paper Duct Insulation
  Perlite Insulation
  POLYISOCYANURATE FOAM INSULATION
  POLYSTYRENE FOAM INSULATION
  RADIANT BARRIERS
  RIGID FOAM USE INDOORS
  Urea Formaldehyde Foam Insulation UFFI
  Vermiculite Insulation

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

• Our recommended books about building design, inspection, and repair, and about indoor environment testing, diagnosis, and cleanup are at the InspectAPedia Bookstore.
• ...

More Information on Building Diagnostic Inspections and Repairs

• Asbestos: How to find and recognize asbestos in Buildings - visual inspection methods, list of common asbestos-containing materials
• Asbestos HVAC Ducts and Flues field identification photos and guide
• Fiberglass: Indoor Air Quality Investigations: Health Concerns About Airborne Fiberglass: Fiberglass in Indoor Air from HVAC ducts, and Building Insulation
• Enviro-Scare: Electric Power Lines, Electromagnetic Fields, Cancer Risk, & "Enviro-Scare" - The Normal Curve Cycle of Public Fear of Environmental Issues
• Dust from the World Trade Center collapse following the 9/11/01 attack: the lower floors of this building contained spray-on fire-proofing asbestos materials.
• Asbestos Information Links: Asbestos Detection, Testing, Recognition, Hazards, Field Photos, and Information Sources, including health-related links such as legal services and information about mesothelioma and other cancers.
• Asbestos Identification and Testing References
• Asbestos Identification, Walter C.McCrone, McCrone Research Institute, Chicago, IL.1987 ISBN 0-904962-11-3. Dr. McCrone literally "wrote the book" on asbestos identification procedures which formed the basis for current work by asbestos identification laboratories.
• Stanton, .F., et al., National Bureau of Standards Special Publication 506: 143-151
• Pott, F., Staub-Reinhalf Luft 38, 486-490 (1978) cited by McCrone

InspectAPedia® Home & Site Map - Building & Environmental Inspection, Testing, Diagnosis, Repair, & Problem Prevention Advice: In-depth research & advice on diagnosing, testing, correcting, & preventing building defects & indoor environmental hazards. Unbiased information, no conflicts of interest.

The Mold Information Center: What to Do About Mold in Buildings, When and How to Inspect for Mold, Clean Up Mold, or Avoid Mold Problems

Use this simple, economical mold test kit by following our instructions on how to collect and mail mold samples to our lab

Environmental Inspection, Testing, & Diagnosis On-Site IAQ, Gas, Air Testing, Mold Investigation, Sick Building Diagnosis, Lab Services, & Remediation Plan Preparation - indoor air quality testing, problem source determination, supporting lab work, written remediation plan addressing removal of environmental and other hazards and prevention of their recurrence.

Building Inspection, Problem Diagnosis, Forensic Investigation & Testing, Repair Consulting

Contact Daniel Friedman for website content suggestions or for fee-paid consulting