Polypropylene is considered a non-toxic plastic used in various household items, including dog toys and containers. It doesn't contain bisphenol A (BPA), phthalates, or other harmful chemicals typically associated with plastic toxicity. When ingested in small fragments, it's unlikely to cause harm due to its inert nature. However, ingestion of larger pieces could pose a risk of physical obstruction in the digestive tract, which can be dangerous and may require veterinary intervention. It's important to supervise your dog when they're playing with toys made of polypropylene to avoid accidental ingestion of large pieces.

ABS (Acrylonitrile Butadiene Styrene) cement and PVC (Polyvinyl Chloride) cement are formulated differently due to the materials' distinct chemical compositions. While ABS cement is designed specifically for bonding ABS plastic, PVC cement is tailored for PVC materials. Using ABS cement on PVC can result in a joint that is not as strong or reliable as one made with the appropriate PVC cement, because the solvent in ABS cement may not properly soften and fuse the PVC surfaces. However, there exist special transition cements made specifically for joining ABS to PVC, which provide a strong bond between these two types of plastics when a direct connection is necessary. For optimal results and adherence to building codes, it's recommended to use the cement intended for the specific type of plastic you're working with or a certified transition cement for mixed material connections.

Plexiglass is neither polyethylene nor polypropylene. It is actually a brand name commonly used to refer to acrylic, which is a type of plastic officially known as polymethyl methacrylate (PMMA). While both polyethylene and polypropylene are polymers used in a wide range of applications due to their versatility and durability, PMMA offers unique properties like superior clarity, weather resistance, and excellent light transmission, making it a popular choice for applications requiring clear visibility and durability such as windows, shields, and various design projects.