To determine the most relevant factor when discussing health-based international standards for drinking water, we need to consider what these standards emphasize to ensure water safety and quality for human consumption.

International standards for drinking water are designed to ensure that water is safe for human consumption. The primary focus of these standards is to control the presence and concentration of harmful contaminants that may pose health risks. This includes a wide range of chemical, physical, and biological contaminants that can arise from environmental factors, human activities, or industrial processes.

Let's examine each option to identify the correct answer:

1. Permissible limits for water storage used in households: This relates more to the handling and storage of water rather than its composition. While important, it doesn't directly relate to the contaminants in the water itself.
2. Permissible limits for minerals present in drinking water: While minerals are a component of water quality, many minerals are naturally present in water and are often beneficial up to certain levels. The focus of health-based standards is primarily on contaminants, not the minerals themselves.
3. Permissible limits for contaminants in water: This option is the most relevant to health-based standards, as it directly addresses the control of substances that could be harmful to human health. These standards outline acceptable concentration levels for a wide range of contaminants, including microbial pathogens, heavy metals, pesticides, and industrial chemicals.
4. Permissible limits for temperature in drinking water: Although temperature can affect water quality and taste, it is not a primary concern of health-based standards, which focus more on chemical and biological safety.

Based on the analysis, the correct answer is Permissible limits for contaminants in water. These limits are crucial to ensuring drinking water is safe and meet health protection goals according to international guidelines, such as those provided by the World Health Organization (WHO) and other international regulatory bodies.