Ozone

In the aftermath of the ozone posting, Sue Davis and I had some private
follow-up postings back and forth.  I asked around to a few people just
to see if there was any interest in the non-public postings and there
was. Since my postings look a little strange out of context, I got
permission from Sue to add her mailings to make this whole thing make
more sense.  So here goes:

  Doug,

  Many thanks for your posting about ozone.  I have been looking for
  some factual information about it and have not had much success.  My
  interest grew out of a conversation with a representative of a
  commercial dehumidification company who said that ozone would rid a
  building of odors and not harm materials, furniture, etc. in it. Your
  illustration of what happens to photos from ozone exposure is
  dramatic.  But, are you talking about the levels that might be used in
  building deodorization effort, or ones much higher?

  We do have a small photo archives in our main library building so I'm
  grateful for your advice about them, but does ozone also have a strong
  corrosive effect on plain paper materials, i.e., books? Obviously,
  we've got lots more of them.

  Thanks for any additional info.  And, if you could point to
  bibliographic sources on this subject (mind you, I don't have a
  scientific background at all, so the technical stuff is kinda over my
  head), I'd appreciate that, too.

  ---------------------------

  Sue,

  The Ilford story (which came from one of the engineers at Ilford) was
  indeed a building deodorization effort.

  The bad news is that there really *isn't* any literature.  We've been
  looking at pollution with respect to photographic materials so far,
  but intend to see (some day) what the effects are on other materials.
  There have been quite a number of scientific studies done for various
  reasons, but nothing that really talks about real life problems and
  levels.  Ozone, even at very low levels can be quite active and I
  wouldn't really believe that it could be used without problems.  We
  have found incredible synergies (which reflects the real life since we
  never see individual pollutant gases alone.)

  Let me quote a little from Thompson's The Museum Environment:

      "Ozone has a specific and complete action on unsaturated organic
      compounds, that is to say it will break every double bond on a
      carbon chain with which it comes into contact.  This destroys the
      material.  In this way transverse cracks appear on rubber bands
      which then snap when stretched.

      However attack by ozone does not end with rubber bands.  It is a
      powerful oxidant, that is to say destroyer, of almost all organic
      material.  The effect of ozone on certain materials such as
      cellulose may be due to its partial conversion to hydrogen
      peroxide by reaction with water.

      The reader will hardly need to be reminded that paintings,
      textiles, archival materials, furniture, biological specimens,
      leather, fur, feathers, etc., are all made wholly or predominantly
      of organic material, and that therefore ozone is extremely
      dangerous in the museum.  Ozone also increases the rate of
      oxidation of silver and iron and of sulphidation of silver and
      copper.  Hopefully one may suppose that the visitors may in this
      case help conservation, since every inhalation is likely to
      destroy all the ozone in the breath."

  He goes on to say:

      "Ozone is interesting.  Though of course it can gain access [sic]
      through open windows, in non-ventilated rooms it has a very short
      indoor life, being rapidly destroyed by organic materials
      including presumably by human beings and exhibits!  Its half-life
      in an unoccupied bedroom has been estimated at six minutes (that
      is to say its concentration is halved in six minutes)."

  Lastly he says:

      "The possibility of ozone acting as an accelerator of
      photo-oxidation has been raised by Briner.  One could conclude
      from a paper by him that each molecule of ozone reacting with the
      surface of an exhibit causes around 100 000 oxygen molecules also
      to react with it.  If this is the case, concentrations of ozone
      much lower than the natural background level could influence the
      deterioration of all organic material in antiquities.  This is at
      present an open question, but it is obviously of prime importance
      for future scientific research on preservation."

  There are a number papers (in such places as the ACS Journal)
  referenced. These are all technical publications, but I can send the
  footnotes list if you want it.  It is interesting that we see similar
  things with laser printers and photocopiers.  In the old days, rubber
  gaskets and things were deteriorating at an incredible rate.  The
  manufactures of laser printers and copiers ended up putting ozone
  filters into their machines just to lower the levels of ozone enough
  that rubber parts lasted a reasonable time.

  In our own early studies, we used ozone levels that were 10 to 100
  times normal city levels.  (Admittedly high, but we wanted to do some
  rough screening experiments and low levels would take too long.)  Our
  current project (just started weeks ago) uses much more realistic
  levels of pure gases and gas mixtures.  Even these are a little high,
  but match typical peak city levels.

  ------------------------

  Doug,

  Yes, please send me citations from the technical journals if it is not
  too much trouble.  If I really get stumped, I can always call on our
  university chemistry dept.  You have provided me more information in
  these two posts than I have been able to glean from everywhere else
  combined.  Thanks for sharing your expertise.

  ------------------

  Sue,

  Let me give you Thomson's references first and then some other related
  articles.

  1) Campbell, G.G, Schurr, G.G., Slawikowski, D.E. and Spence, E.J.W.,
      "Assessing Air Pollution Damage", Paint. Technol., 46, June(1974)
      59-71.

  2) Briner, E., "Accelerating Action of Ozone in the Autooxidation
       Process", Advances in Chemistry Series.  Ozone... American
       Chemical Society, March (1959) 184-94.

  3) Scott, G., Atmospheric Oxidation and Antioxidants, Elsevier (1965)
  97.

  4) Graedel, T.E., Frnley, J.P. and Kammlott, G.W., "Ozone- and
      Photon-enhanced Sulfidation of Copper", Science (11 May 1984)
      599-601.

  [Thomson is English and worked as an advisor to the National Gallery
  in London, hence the form of the dates. - Doug]

  5) Cox, R.T., Eggleton, A.E.J., Derwent, R.G., Lovelock, J.E. and
      Pack, D.H., "Long-range Transport of Photochemical Ozone in
      North-west Europe", Nature, 8 May (1975) 118-21.

  Most of the articles that have been written about indoor air pollution
  have been with respect to health and safety or the environment.  There
  is very little written about art and archival materials.

  Other references I will list in two groups -- one directly related to
  art and archive materials and the other more general about ozone and
  air.

  I.  Primary References (in no particular order.)

  1) Whitmore, P.M., and Cass, G.R., "The Ozone Fading of Traditional
      Japanese Colorants", Studies in Conservation 33 (1988) 29-40.

  2) Grosjean, D., Whitmore, P.M., De Moor, C.P., Cass, G.R. and Druzik,
      J.R., "Ozone Fading of Organic Colorants:  Products and Mechanism
      of the Reaction of Ozone with Curcumin", Environ. Sci. Technol.,
      Vol 22, No. 11 (1988) 1357-1361.

  3) Cass, G.R., Nazaroff, W.W., Tiller, C., and Whitmore, P.M.,
      "Protection of Works of Art from Damage Due to Atmospheric Ozone",
      Atmos. Environ., Vol 25A, No.2 (1991) 441-451.

  4) Whitmore, P.M., Cass, G.R., Druzik, J.R., "The Ozone Fading of
      Traditional Natural Organic Colorants on Paper", JAIC 26(1987)
      45-58.

  5) Druzik, J.R., Adams, M.S., Tiller, C. and Cass, G.R., "The
      Measurement and Model Predictions of Indoor Ozone Concentrations
      in Museums", Atmos. Environ., Vol 24A, No. 7 (1990) 1813-1823.

  6) Grosjean, D., Whitmore, P.M., Cass, G.R., and Druzik, J. R., "Ozone
      Fading of Triphenylmethane Colorants: Reaction Products and
      Mechanisms", Environ. Sci. Technol., Vol. 23, No.9 (1989)
      1164-1167.

  II. Secondary (but possibly interesting to you.)

  1) Nazaroff, W.W. and Cass, G.R., "Mathematical Modeling of Chemically
      Reactive Pollutants in Indoor Air", Environ. Sci. Technol., Vol
      20, No. 9 (1986) 924-934.

  2)  Schere, K.L., "Modeling Ozone Concentrations", Environ, Sci.
      Technol., Vol 22, No. 5 (1988) 488-495.

  3) Sakugawa, H., Kaplan, I.R., Tsai, W. and Cohen, Y., "Atmospheric
      Hydrogen Peroxide: Does it Share and Role with Ozone in Degrading
      Air Quality?", Environ. Sci. Technol., Vol 24, No 10 (1990)
      1452-1461.

  [I included the last article just because ozone with light and
  moisture (humidity) is a pathway to hydrogen peroxide formation. -
  Doug]

  I did not include article that strictly dealt with the consumption of
  ozone in the outside environment or the (outdoor) environmental impact
  of ozone.

  This list should cover most of the articles currently available (with
  regard to the museum/archive/library environment), although there may
  be more articles that we are not aware of.

  ...

-Douglas Nishimura
Image Permanence Institute

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                  Conservation DistList Instance 7:34
                Distributed: Wednesday, October 20, 1993
                        Message Id: cdl-7-34-004
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