Which plastic is often used in the production of toys and refrigerator linings?

The selection of HIPS, or High Impact Polystyrene, as the correct answer is backed by its desirable properties that make it particularly suitable for the production of toys and refrigerator linings. HIPS is known for its excellent impact resistance, which is critical for toys that undergo rigorous play and handling, ensuring durability and safety for children.

Additionally, HIPS has good chemical resistance and can be easily molded and manufactured into complex shapes, making it versatile for various toy designs. In the context of refrigerator linings, its insulating properties and resistance to temperature variations make it a practical choice, as it can effectively maintain the interior environment of the refrigerator while being easy to clean and maintain.

Other options, while having their own applications, do not match the specific attributes that HIPS provides for these particular uses. PMMA is more commonly used for products needing clarity and rigidity, such as lenses or displays, while HDPE is favored for its strength and chemical resistance in items like containers and piping. ABS, although used in many applications including toys, may not offer the same level of impact resistance in the context measured here, particularly when comparing it directly to the widespread use of HIPS in both toys and refrigerator linings.