CHAPTER 24 ■ BODY BUILDINGBe aware that acetone can destroy some types of plastics, but the M&M’s candy tube is unaffected
because it is made out of polypropylene thermoplastic, as you can see from the recycling symbol on the
bottom (see Figure 24-17). Polypropylene is very resistant to chemicals. So, acetone doesn’t harm the tube.
Figure 24-17. Recycling symbol indicates tube is polypropylene
Figure 24-18. Acetone destroying a standard LEGO brick
The LEGO cross axles, the M&M’s candy tube, and the Ziploc container are all polypropylene. By the
way, the chemical resistance of polypropylene means it is nearly impossible to paint or permanently attach
stickers to those portions of the robot’s body.
Standard LEGO bricks are made of ABS (acrylonitrile butadiene styrene) thermoplastic. Don’t try
cleaning your LEGO bricks with acetone; they’ll decompose (see Figure 24-18). Also unlike polypropylene
products, LEGO bricks are not dishwasher safe; they’ll melt.