Apart from drinking water, irrigation water contaminated with arsenic (As) is a significant source of human As exposure via water-soil-crop transfer. Reducing As intake through food consumption is critical to the public health response in As-contaminated areas, especially in Asia. Rice is the most common staple food in many of these contaminated sites and As exposure from rice consumption is well-researched. While drinking water has a permissible, or guideline value for As, quantifying guideline values for soil and irrigation water is required to help reduce As exposure from rice intake. This chapter covers the status of As contamination in the rice ecosystems of Asian counties and outlines the interrelationship of As in irrigation water with soil and rice grain. Further, a piece of comprehensive information has been provided regarding the existing guideline values for As in soil and irrigation water as recommended by different organisations. Insight has been given to attempts made by different researchers to derive a guideline value for soil using machine learning algorithms. It was observed that 14 mg kg−1 of soil total As and 5.70 mg kg−1 of bioavailable As might be considered as guideline value to ensure safe cultivation of rice. Lastly, a pathway for future research directions has also been outlined.