Day 010 - 11 Jul 94 - Page 65
1 of the ozone molecule which is instead of 02, 03, three
oxygen molecules, and then in the presence of chlorine
2 atoms that are carried by gases, like HCFC or CFC, and
that react in the atmosphere to the ozone and break the
3 third oxygen off the ozone, molecule, that the HCFCs would
be less damaging in there -- I presume they are referring
4 to scientific experiments that demonstrate that, but the
difference is associated with the degree of reactability
5 and the stability of the HCFC molecule as compared to the
CFC molecules.
6
Q. Can I suggest to you that a summary of the evidence at the
7 time was something like this, the HCFC-22 molecule being
not fully halogenated was much more unstable than the
8 CFC-12 molecule, with the consequence that it was thought
that it broke up or reacted in a lower atmosphere, the
9 troposphere, whereas the CFC-12 molecule was transported
to the stratosphere which is where the ozone layer was and
10 did its damage there?
A. Well, I would accept that explanation, but I would add
11 that the chlorine molecules themselves still remain and
they are transported into various layers of the
12 atmosphere, may be just as dependent upon other materials,
which the point to make there is that if indeed HCFC is
13 only 5 per cent is damaging to the ozone layer as CFC
molecules, then we can presume that some of that material
14 is, nonetheless, reaching the upper levels of the
atmosphere and that the scientific models that are being
15 used to describe the difference in this process have some
limits.
16
Q. Indeed.
17 A. And predictability.
18 Q. That is absolutely right. What we must, if you will
forgive me, discard in discussion is that false friend
19 "hindsight". It is now known or thought or believed with
a good deal of reservation perhaps, that is exactly what
20 does happen, and cannon of ozone depletion or potential
ozone depletion which is now used is chlorine loading
21 which has not the same characteristics as the old ozone
depletion potential. Did you know that?
22 A. No.
23 Q. That change in perception did not arise until late 1989 or
early 1990, did you know that?
24 A. I am not aware of that, no.
25 Q. Were you aware that the reason why in 1987 HCFC-22 was
thought to be more environmentally or ozone friendly than
26 CFC-12 or 11 was that that knowledge was not then
available? Did you know that?
27 A. Well, I am aware that the manufacturers made certain
claims regarding HCFCs as an alternative gas.
28
Q. Manufacturers? Would you care to look at the document?
29 You should find behind you some pink files looking like
that. They are fat things. They might be in the shelf
30 behind you. I want you to get out V. Have you got that
pink one? I suggest you put it on top of your other
