The point is the Peltier module are 100% save and there is quite no way to explode or put out some Toxic stuff out.
This is absolutely stupid. They stopped using toxic, dangerous refrigerants (such as ammonia) in compressor systems about 100 years ago, and they do not just explode randomly either.
The Peltier's power supply or wiring can as well catch fire, and the PVC insulation will put out very toxic smoke.
Refrigeration technology is about as safe as anything can be.
Note that it's often completely impractical to provide enough cooling with Peltiers for preserving foods, or keep drinks cool. Even if that is possible, the energy consumption is so high that it's an environmental disaster. When done absolutely right, it's about 10-20 times less efficient than just the normal refrigerator, but it can be much worse than that, and often is.
Re: the latter Peltier module: I wouldn't use heatpipes on the Peltier's hot side. Heat pipes can transfer great amounts of heat, but the rated degC/W is not a constant but only applies at a certain high dT, since there is an evaporative action going on. While this works great when you cool things that can work at higher temperature differences (such as semiconductors, CPUs...), remember, the Peltier's hot side needs to be cooled really close to the ambient to be of any use. For example, a CPU can work fine at 80 degC, but the Peltier hot side needs to be at 30degC! Hence, I have always used either active (pumped) water cooling, or very large, thick aluminium heatsinks - copper would be even better.