I found a paper (TECHNICAL BULLETIN 0314) publised by dyplast products with a benchmarking between cellular glass and phenolic foam. These comparisons could be a problem in Europe but are allowed in the USA. Due to the large risk for a law suit in the USA, I may assume that the given facts in the paper are correct. But it is not sure that all relevant facts are given. In that perspective, I found another paper, published by The Dow Chemical Company, Midland, MI (U.S.A.). Also in this case, I may assume that the facts are correct.
In the last paper, I found the following:
- Claimed benefits were high insulation value and excellent fire resistance. High moisture absorption potential and residual acid present in the foam allegedly resulted in significant corrosion issues. Class action lawsuits were filed against corporations in the early 1990’s. Past litigation in North America focused on corrosion allegedly caused by phenolic foam used in metal deck roofing applications. The resultant roofing failures and subsequent litigation are still fresh in the minds of the building community.
- Commercial phenolic foam insulation is made from a resole resin in the presence of an acid catalyst, blowing agents and surfactants. The resole resin is synthesized via a base catalyzed reaction of phenol and formaldehyde in a 1:2 ratio where there is a twofold excess of formaldehyde in the reaction mixture.
- Liquid chromatography (LC) was used to determine
the amount of unreacted formaldehyde monomer
remaining in the phenolic foam samples. The total
residual formaldehyde found in both phenolic foam
samples ranged from 137 – 264 ppm. (Table 7)
As a comparison, the raw materials used to produce
PIR and XPS foam do not measure a reportable level of
- The phenolic samples evaluated in the modified test result in a solution with a pH less than 4.0. This could raise concern regarding potential corrosion issues when these products are used in contact with iron and steel.
- The water absorbed by the foam samples over the 90 day test period had a detrimental impact on thermal conductivity. After 7 days of submersion, both phenolic samples had lost enough thermal resistance to perform inferior to both PIR and XPS foams. As the duration of the test continued, phenolic Foam A dropped to 50% of the original measured thermal resistance performance. Phenolic Foam B dropped to 35% of the original performance. Comparatively, the XPS maintained 97% over the same period, and the PIR sample maintained 82% of its original performance.
In a prelimnary Britisch Standard, BS_xxxx_1_7_2010 , I found in Annex A (informative):
- b) In designing insulation systems with phenolic foams, care should be taken to prevent ingress of water.
- c) Adequate precautions should be taken to prevent moisture being interposed between metal and foam surfaces.
- d) For normal use, rigid phenolic foam materials are suitable for use in the temperature range – 180 °C to + 120 °C.
NOTE The lower temperature limit is selected to indicate the unsuitability of these materials for insulation of liquid oxygen plants. These materials can however be used at temperatures down to – 200 °C provided that precautions are taken to prevent the condensation of atmospheric oxygen in or on the insulation.
This seems to confirm the above about water absorption and corrosion.
About formaldehyde, I found the following on Wikipedia.
- There is also research that supports the theory that formaldehyde exposure contributes to reproductive problems in women. A study on Finnish women working in laboratories at least 3 days a week found a significant correlation between spontaneous abortion and formaldehyde exposure, and a study of Chinese women found abnormal menstrual cycles in 70% of the women occupationally exposed to formaldehyde compared to only 17% in the control group. There have been no studies done on the effect of formaldehyde exposure on reproduction in men.
- The formaldehyde theory of carcinogenesis was proposed in 1978. In 1987 the U.S. EPA classified it as a probable human carcinogen, and after more studies the WHO International Agency for Research on Cancer (IARC) in 1995 also classified it as a probable human carcinogen. Further information and evaluation of all known data led the IARC to reclassify formaldehyde as a known human carcinogen associated with nasal sinus cancer and nasopharyngeal cancer. Recent studies have also shown a positive correlation between exposure to formaldehyde and the development of leukemia, particularly myeloid leukemia.
- Indeed, this IARC paper clearly states: Formaldehyde is carcinogenic to humans (Group 1).
About the IARC classification, we find in Wikipedia:
- Group 1: carcinogenic to humans: There is enough evidence to conclude that it can cause cancer in humans.
- Group 2A: probably carcinogenic to humans: There is strong evidence that it can cause cancer in humans, but at present it is not conclusive.
- Group 2B: possibly carcinogenic to humans: There is some evidence that it can cause cancer in humans but at present it is far from conclusive.
- Group 3: not classifiable as to carcinogenicity in humans: There is no evidence at present that it causes cancer in humans.
- Group 4: probably not carcinogenic to humans: There is strong evidence that it does not cause cancer in humans. Only one substance – caprolactam – has been both assessed for carcinogenicity by the IARC and placed in this category.
We can also state the following about GLAPOR cellular glass:
- uses during production or contain only products belonging to a IARC group 3.
- is absolutely non-combustible like every mineral
- is absolutely vapor tight
- does not absorb water at all
By combining the original benchmarking with the above facts, we come to a more profound benchmarking. Can we compare phenolic foam with GLAPOR cellular glass? Can we compare a Elon Musk Tesla car with a software manipulated diesel car? That is up to the reader of this blog, we only made the extension of the original benchmark, to be used by every cellular glass sales man on earth.
Pingback: Comparison of Closed Cell Elastomeric Insulation To Cellular Glass | BELGLAS BVBA