Bags of material we send to customers, we've had several complaints that when certain substances are opened in their bags, they are very dusty compared to other substances...is there any devices out there which can test how dusty a substance is before its sent away (this might be a stupid question, but im generally curious)

would a dust lamp work? http://www.hse.gov.uk/pubns/mdhs/pdfs/mdhs82-2.pdf Difficult to say more without further information.

'material' is mainly animal feeds...want to possibly test the bags by dropping them few inches of the ground, or by opening them or pouring into containers, and seeing if there is a large amount of dust that accumlates

Try www.heubachcolor.de Their Dustmaster Type II claims to be a standardised method as per EU Regulation 85/157 "Animal Feed Additives". We were considering one at one time but for what we were going to use it for didn't justify the cost: Over 18,000 Euro.

The brand name of the machine I used was Cilas - a French manufacturer. You dispersed a small amount of the material in IPA (that's isopropyl alcohol, not the other kind) and the machine did all the rest, giving a graph as output. It was a big machine about the size of a photocopier and the pride of my lab.

To measure dust levels with a sieve you also need a sieve shaker, as material doesn't go easily or reproducibly through a fine sieve and to get comparable results, you have to give the same large amount of shaking to the sieve - which is a job for a machine not a human. The sieve shaker is a thing that you stack the sieves on and then it vibrates them.

As far as I understand, the detergent and animal feed industries tend to control how "dusty" their products are ie how likely their product will create a dust problem for the end user. This is different to measuring particle size (although I agree that this will influence the outcome) or measuring dust levels when used for its end purpose. They are looking at ensuring that each batch is below a maximum level of dustiness. Measuring the dustiness of bulk materials is covered by European standard EN 15051:2013 - Workplace exposure: Measurement of the dustiness of bulk materials. It comes in three parts: EN 15051-1:2013 Requirements and choice of test methods. EN 15051-2:2013 Rotating drum method. EN 15051-3:2013 Continuous drop method. Various literature references indicate that the rotating drum method more closely reflects the practical handling of bulk powders / granules. It is based on a method developed by the UKs HSL. The Dustmaster I mentioned in an earlier post is of this type. If it is only to be used for internal comparison testing, an alternative to buying a unit may be to make something similar yourself. Hope this is of some help. Barry

Sounds as if you don't have enough binding agent (fat/molasses?) if the feed is dusty - surprised your customers are not complaining (ours used to) which may need input from the quality dept to ensure the mix is right or that feed is not drying out too much??