The draft dust effect standard is written as a recommendation, a document that gives a mixture of guidance "should" statements and mandatory "shall" statements. A great variety of materials might be suitable for dust effects, either as dust lying on props and scenery or as aerosol clouds, so it does not specify exactly what dust must be. However, the standard will help people to avoid inappropriate materials, to select those that are least likely to cause health or safety problems, and to use them with care.
(Jim Evans)
