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D3069-94 – Standard Test Method Technical Guide
This article covers the ASTM D3069‑94 (Reapproved 2013) standard, which provides a reliable method for measuring the delivery rate of aerosol products. The test is essential for evaluating valve performance and is often a prerequisite for both biological and storage testing.
📋 Test Method Summary
This test method determines the delivery rate of an aerosol dispenser by measuring the quantity of material expelled through the valve over a precisely controlled period. The temperature of the dispenser and the duration of discharge are carefully controlled to ensure good reproducibility. Delivery rate tests assist in evaluating one aspect of valve performance and are considered a prerequisite for biological and storage testing.
⚙️ Apparatus and Specimen Requirements
The key apparatus includes a water bath with precise temperature control, a balance accurate to 0.1 g, and a stop watch or electric timer. The test specimen must have its protective cover and paper label removed, but the button or actuator must remain. For foam spouts, nonessential plastic should be cut away before testing.
| 🟦 Parameter | 📏 Specification | 🎯 Notes |
|---|---|---|
| Water Bath Temperature (Standard) | 70 ± 0.1 °F (21 ± 0.05 °C) | For most aerosol products |
| Water Bath Temperature (Insecticides) | 80 ± 0.5 °F (26 ± 0.25 °C) | To match Peet‑Grady test requirements |
| Equilibration Time (Anhydrous) | 15 min | For essentially anhydrous products |
| Equilibration Time (Water‑based) | 25–30 min | For viscous or water‑base products |
| Balance Resolution | 0.1 g | Weigh to nearest 0.05 g |
💡 Tip: Adding approximately 0.03 % sodium nitrite (NaNO₂) to the water bath can prevent minor rusting of some tinplate dispensers.
📝 Procedure Steps
The procedure involves the following key steps:
- Activate the valve for a few seconds, then remove any valve cup impingements, and weigh the dispenser to the nearest 0.05 g.
- Place the dispenser upright on the shelf in the water bath, spaced 1 inch apart and covered with 1 inch of water.
- Circulate the water with the mechanical stirrer and hold for the required equilibration time (15 min for anhydrous, 25–30 min for water‑based products).
- Discharge the dispenser for a controlled time while maintaining the test temperature, then reweigh to determine the delivery rate.
⚠️ Safety Note: The user of this standard must establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
❓ Frequently Asked Questions
🔍 Why is temperature control critical in delivery rate tests?
Temperature significantly affects the pressure and viscosity of the product, which influences the delivery rate. The standard requires precise temperature control within ±0.1 °F (0.05 °C) to ensure reproducibility.
💡 How should the test specimen be prepared?
Remove the protective cover, paper label, and all other detachable materials from the dispenser, except the button or actuator. For foam spouts, cut away nonessential plastic before testing.
⚡ What is the significance of delivery rate in valve performance?
Delivery rate tests help evaluate valve performance, ensuring consistency across dispensers. They are often a prerequisite for both biological and storage testing.
📌 Can this test be applied to all aerosol products?
Yes, the method is generic but requires adjustments for product type. For example, equilibration time varies from 15 minutes for anhydrous products to 25–30 minutes for water‑based products, and the water bath temperature may differ for insecticides.