Details

All reagents have a shelf life, whether they are liquids, powders, crystals, tablets, or test-strip pads. If kept dry, powders and crystals are very stable; acids are also long lived. Date of manufacture is not the controlling factor when it comes to shelf life-storage conditions are more important. As with all perishables, reagents are sensitive to environmental influences and will last longer under controlled conditions.

• Storing reagents at a consistent temperature in the range of 36°-85°F (2°-29°C); extreme temperature fluctuation, say from a refrigerator to a hot car trunk, causes reagents to deteriorate.
• Keeping them out of prolonged direct sunlight. (Note: Their brown plastic bottles help protect very light-sensitive reagents.)
• Segregating reagents from containers of treatment chemicals.
• Replacing caps immediately and tightening them carefully so that exposure to air and humidity is limited.
• Avoiding switching bottle caps, placing bottle caps on soiled surfaces, repouring reagents into contaminated containers, or touching test strip pads.