That’s a fair question, and one we usually answer this way …
ASTM has specified 3 types of Zinc Dust:
- Type I
- Type II
- Type III
What differentiates these types are the total zinc content, the metallic zinc content and the level of impurities for such things as lead and cadmium.
A comparison of the 3 types looks like this:
| Description | ASTM Type III | ASTM Type II | ASTM Type I |
|---|---|---|---|
| Total Zinc Content (% minimum) | 99% | 98% | 97.5% |
| Metallic Zinc Content (% minimum) | 97% | 94% | 94% |
| Lead Content (% minimum) | 0.002% | 0.01% | 0.20% |
| Cadmium Content (% minimum) | 0.001% | 0.01% | 0.06% |
So how does our Zinc dust stack up to the standards?
| Description | PZM's Ultra Pure Zinc Dust | ASTM Type III | ASTM Type II | ASTM Type I |
|---|---|---|---|---|
| Total Zinc Content (% minimum) | 99% | 99% | 98% | 97.5% |
| Metallic Zinc Content (% minimum) | 97% | 96% | 94% | 94% |
| Lead Content (% minimum) | 0.002% | 0.002% | 0.01% | 0.20% |
| Cadmium Content (% minimum) | 0.001% | 0.001% | 0.01% | 0.06% |
Unlike most other Zinc Dust Producers, we only manufacture and sell Type III – the most environmentally friendly of the three. PZM only uses Special High Grade Zinc (SHG) as our raw material feedstock, while some producers use only High Grade Zinc Metal which has higher levels of impurities. Other producers will use Secondary Zinc Metal, such as bottom dross, which has the highest levels of impurities.
Our other secret is that we utilize a Continuous Batch Process. 12 months a year, 7 days a week, 365 days a year, we never stop producing which provides an end-product with much more consistent physical and chemical properties, than does batch processing.
“We were green before green was cool…”
From our beginnings back in 1969, our founders saw the importance of protecting the environment and the worker. Harmful environment and worker exposure to heavy metals like lead & cadmium should always be an important concern. The first step in meeting these concerns is to select a zinc dust with ultra low impurities.
So when you’re specifying Zinc Dust, think of the worker and the environment. Specify Ultra Pure Zinc Dust from PZM … “It’s the greenest way to protect the Big Blue Marble.”
Tags: ASTM, metallic zinc, PZM, Special High Grade Zinc, Ultra Pure Zinc Dust, zinc dust
