When it comes to ensuring safety and quality in your toy models, choosing the right materials is crucial. Here are some suggestions for materials that you can consider:

1. Non-Toxic Plastics: Look for plastics that are labeled as non-toxic and free from harmful chemicals such as phthalates, lead, or BPA. These materials should meet safety standards for children's toys and ensure that they can be safely handled and played with.

2. Natural and Sustainable Materials: Consider using natural and sustainable materials such as wood or bamboo for certain parts of your toy models. These materials are often durable, eco-friendly, and have a pleasing tactile experience.

3. Soft and Rounded Edges: Ensure that any hard plastic or wooden parts have smooth and rounded edges to minimize the risk of injury during play. Avoid sharp or pointed edges that could potentially cause harm.

4. Sturdy Construction: Ensure that your toy models are well-constructed and can withstand regular play. Reinforce any movable parts or connections to prevent breakage or detachment during use.

5. Safety Certifications: Look for safety certifications such as ASTM F963 or EN71, which indicate that the materials and design of your toy models meet specific safety standards. These certifications provide assurance to consumers that your products have been tested and deemed safe for use.

Additionally, it's important to conduct thorough research on materials and suppliers to ensure their reliability and adherence to safety standards. You may also consider consulting with experts or industry professionals who specialize in toy production for further guidance on materials selection.

By prioritizing safety and quality in your choice of materials, you can create farming toy models that not only provide an enjoyable play experience but also instill confidence in your customers.