I have some Round Up and you got me wondering about it my self. So I e-mailed the people who make the stuff. If any one wound know it would be them. Here is the e-mail I got back
Thank you for contacting us concerning RoundUp® products. As always, it is our goal to make sure that
our customers are completely satisfied with our products and services.
We appreciate your comments on the information on our RoundUp website. We appreciate getting
feedback on our products and services. We take all comments very seriously, Mr. Henderson, and we
have shared your concerns with our Website Administrator.
Roundup Weed & Grass Killer Concentrate has a shelf life of a minimum of eight years. The product may
last beyond the minimum time period though. Many variables in storage conditions can affect the shelf
life of a product, Mr. Henderson. Roundup Weed & Grass Killer Concentrate will not be fully effective one
day and ineffective the next; the product will gradually lose its effectiveness over time. Store both
unopened and opened product containers in a cool, dry place and protect them from extremes in
temperature. Freezing temperatures, for example, won't affect the product, but may cause damage to the
container and could result in a chemical spill. Stored correctly, your product will last at least the minimum
number of years and probably longer.
Mr. Henderson, we recommend that you plan ahead, and mix only as much of this product as you will
actually use.
You may store diluted Roundup Weed & Grass Killer Concentrate for up to 6 months. After that, the
surfactant, or sticking agent in the RoundUp, breaks down due to impurities in tap water. RoundUp
Ready-to-Use products have a 4-year shelf life because they have an added ingredient to prevent this
breakdown in the surfactant. If you store diluted product after use, be sure to mark the storage container
to note both the contents and the date the product was mixed.
Again, thank you for taking the time to let us know of your concerns. Please do not hesitate to contact us
if we can be of any additional help to you.
Glen Kussow
Consumer Response Representative
The Scotts Company and Subsidiaries
14111 Scottslawn Road
Marysville, OH 43041
Ref # 3038730