Is propylene glycol in antifreeze?

Could you please clarify whether propylene glycol is a common ingredient in antifreeze? I've heard that it's sometimes used as a substitute for ethylene glycol due to its lower toxicity, but I'm not entirely sure if this is accurate. Additionally, I'm curious about the potential implications of propylene glycol being present in antifreeze, especially in terms of its environmental impact and the potential health risks associated with exposure. Thank you for your time and consideration.