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I am pleased to see that efforts are being made to regulate devices
that emit ozone into the indoor environment. The regulation to my
understanding requires any indoor air cleaning device (IACD) to
comply with an "emission concentration not exceeding 0.050 ppm
O3". I assume this level is selected based on current health data,
or lack thereof, on the effects of ozone at less than .050 ppm
concentration in the space. In addition this coincides with the 
same level as prescribed by the FDA standard for medical devices.
Herein, I would offer the following comments for consideration:

1) The FDA standard was set as an "accumulation level" within a
space. It is important to note that the .050 ppm concentration
limit is based on all sources which may contribute to the
resultant indoor ozone concentration. This would include not only
contribution from the use of the ozone generating IACD but also
(primarily) that from outdoor air. It is well-established in the
literature that typical indoor/outdoor ratios of ozone range from
0.2 to 0.7 (Weschler, 2000). The point being made is that the
regulation proposed will limit the emission concentration, within
a reasonably sized space, from the IACD to less than .050 ppm. To
fully evaluate the indoor accumulation of ozone, one must consider
not only contributions from indoor sources but also that from the
outdoor environment. The broader scenario of including outdoor air
sources should also be considered in the final evaluation as to
resultant indoor ozone accumulation and whether or not it is below
the 50 ppb level related to the FDA Standard (note:it is recognized
that the authors of the CA regulation are only citing the FDA limit
as one of the Standards currently in place; thus the information
provided here is for reference purposes only). Still, the current
proposed CA regulation is the first of its kind, with substance,
on IACDs and goes beyond any other Standard on IACDs. This is
unequivocally a step in the right direction.

2)Whereas the proposed emission concentration standard in the CA
regulation is currently set at 0.050 ppm, I would hope that this
limit is reviewed on a periodic basis to account for the abundance
of ongoing research on the effects of ozone AND the byproducts of
ozone indoor-initiated reactions. The continued research in this
field may warrant more stringent ozone limits in the near future
based not only on the harmful effects from breathing ozone, but
also from the effects of  the byproducts of indoor reactions
resulting in irritants such as aldehydes, ketones, organic acids,
and ultrafine particles.