How should concentrated chemicals be handled when preparing them for use?

When preparing concentrated chemicals for use, dilution is the critical step to ensure safety and effectiveness. Concentrated chemicals can be hazardous in their undiluted form, posing risks such as chemical burns, respiratory issues, or environmental harm. By diluting a concentrated chemical with an appropriate solvent, the chemical is brought to a safer concentration that can be handled more easily and used effectively for its intended purpose.

Pouring concentrated chemicals directly without dilution could lead to dangerous reactions, improper pH levels, or insufficient effectiveness, depending on the application. Mixing or shaking concentrated chemicals, as suggested in another choice, might not achieve the proper dilution and could exacerbate safety risks due to the potential for splashes or spills. Filtering or evaporating concentrated chemicals is not appropriate for preparing them for use, as these processes are usually related to purification or concentration tasks rather than preparation for application.

Therefore, the recommended approach involves diluting the concentrated chemicals to ensure they can be used safely and effectively.