Medved: The neon inside the Philips HPI family of quartz MH lamps, don't reduces the lamp life. They have still the same life as other quartz MH lamps (Osram HQI).

According to Wikipedia, Kr85 have a half-life of 10.756 years, meaning that its radiation is so low, that it isn't dangerous at all.
Also Throium in its natural isotope, Thorium-232, have a half-life of 14.05 billion years.
So why they were banned? They are safe to use in starters and MH lamps.

Because somebody who is not familiar with the science brought up unbased concerns ?

Thorium is a natural, long lived isotope, but because of the long half life, you have to put there quite a large amount of it in order to get the same stimulation level as from some short living replacement. So when the lamp reach end of it's life, you have there quite a lot of the highly toxic heavy metals)...

The reason to remove any radioactive material from something like lamps is more to get rid of handling dangerous substances on the manufacturing site, not as much their presence in final products (as there are many techniques to prevent them to leave the assembly). The reason is related to safety procedures required for their handling when in bulk (storage of the radioactive components or materials), as these make them very expensive for the production, so any way to avoid their use is quite strong money saver for the production facility, with strong consequence to the company's financial profits.

Why ? Isn't the amount needed to get a critical mass WAY more than what a lamp factory can ever need at a time ?

Why ? Isn't the amount needed to get a critical mass WAY more than what a lamp factory can ever need at a time ?

It is not about "critical mass", these materials do not undergo chain reaction at all, the related danger is not the "classical" nuclear explosion...

It is about their radiation and frequently even chemical toxicity (Thorium is a nice example) and related dangers.
If they are in the distribution container, the overall radiation of the content of such container exceed the safe levels. The containers usually have the required shielding, but that make them quite heavy and expensive to make and so difficult to handle.
So if the content leave the container in an uncontrolled manner (an accident, fire,...), the radiation become danger for the public around and the environment. To tackle the danger, all the facilities involved have to meet way stronger safety standards (fire protection - so extra equipment and staff, limits for the amount stored on one place - so less smooth production and more frequent shipping), what complicate the production and mean extra costs.
And on top of this is the ability of any radioactive materials to be misused in a "dirty bomb" (a device designed to contaminate the target area by dangerous radioactivity levels), what require extra security measures for all the handling, so again extra costs.

If the materials are already used on some facility, making extra product there is not as large burden, but as related regulation safety and security standards get stronger, the cost of dealing with radioactive substances increase a lot, so the push to get rid of all the related expenses become stronger and stronger.
So no wonder makers replace the radioactive aids by improved designs and even "swallow" some performance degradation (and in marketing sell this with "radioactive free" or similar slogans).