Much confusion exists regarding the Worker Protection Standards and their implementation with chemical products used in the horticulture industry. This is because the standards have been imposed with little guidance as to how to properly implement them.
The confusion is compounded when products with similar active ingredients carry different restricted entry intervals (REIs).
This is true with quaternary ammonium compounds such as PHYSAN 20. The restricted entry intervals for these compounds vary from zero hours to 12 hours. The factors that determine a product’s REI of zero hours include: if the label restricts the product’s use to non-commercial greenhouses, or excludes its use directly on plants.
Growers today need a product that does more than disinfect hard surfaces. A complete integrated pest management program requires disinfection of plant surfaces as well. PHYSAN 20, which is EPA-approved for use directly on plants, is required to carry the maximum 12 hour restricted entry interval on the label.
It is important to note, however, that many of the most common uses of PHYSAN 20 DO NOT require a 12 hour restricted entry interval. The chart illustrates the multiple uses of Physan and the appropriate REI requirements for each.
Physan 20 Restricted Entry Intervals (REIs) By Application
APPLICATION
REI
NOT REQUIREDREI
12 HOURS
Spot treatment of infected plants
Spraying/Soaking Seedlings
Dipping Cuttings
Disinfecting Tools/Surfaces
Evaporative Coolers
Algae Control - Walls/Walkways
Algae Control - Potting Soil
Algae Control - Fountains/Pools
Lawn/Grass/Turf Applications
Soil Drench
Spraying of all plants through entire greenhouse at one time
Localized spraying of plants in large section of greenhouse*
* Only the treated area is subject to REI requirement
Maril Products Inc.
320 West 6th Street, Tustin, CA 92780
1-800-546-7711 | 714-544-7711 | Fax: 714-544-4830
E-mail: physan@earthlink.net