I'm sorry to keep questioning this, but I'm still unconvinced of the explanation...
1. Lets assume we have a VOC-free poison-free booster. The factory glues an ITTF approved topsheet onto a sponge. Now the factory uses a booster on the SPONGE ONLY. Now according to all evidence I've seen, the ONLY effect that the booster has on the TOPSHEET is that it stretches it, which according to you is legal when done in the factory (within ITTF set limits). Sponges are already made with the use of chemical, and are also glued to the topsheet using VOC-based chemical, so the booster is simply part of this factory process. The rubber is aired properly before sold to the public. Legal rubber or not?
2. Lets assume we have a VOC-free poison-free booster. The factory uses a booster on the sponge, BEFORE it's glued onto an ITTF approved topsheet. The rubber is aired properly before sold to the public. Legal rubber or not?
3. A distributor buys a cheap ITTF approved topsheet and a sponge, and applies either on the the methods (1. or 2.) above. This turns a cheap chinese topsheet and sponge combination into a rubber of similar performance to the top-end Tensor style rubber. The rubber is aired properly before sold to the public. Legal or not?
4. A player buys a cheap topsheet and sponge, and applies either on the the methods (1. or 2.) above. This turns his cheap chinese topsheet and sponge combination into a rubber of similar performance to the top-end Tensor style rubber. Legal or not?
In order to answer your 4 scenarios, first I will explain clearly the rule:
- Any post-factory alteration of the equipment (in this case racket covering) is NOT legal. By post-factory, we mean at the distributor level, at the retail level, at the player level, at the reseller level, etc.
- VOC-containing glues are used at the factory level for several applications (gluing the rubber to the sponge, gluing the wood plies to make the racket, etc.). The factory must follow the rules of their government as it relates to VOCs (very strict in Japan, Canada, Germany,etc, but rather lax in China, India, Russia, etc.). In any case, the ITTF advices the factories to air and ventilate the equipment (rackets and racket coverings in this case) using special ventilated racks, which usually eliminate all VOCs (or almost all).
So now, you could answer your questions yourself:
1. Legal (at factory, no VOCs, no poison, properly aired, stretched within limits).
2. Legal (same as above, if I understood correctly)
3. Post factory, not legal
4. Post factory, not legal
The above is according to the current rules (if I understood the scenarios correctly).