Garden Chemical Safety

October 11, 2003

By Suzzanna Walsh, Master Gardener

So, there I was, going through my tool shed one Saturday morning.  I pick up an innocent-looking garden sprayer only to get a spray of some unknown chemical right in the face!  To the refrain of my husband hollering "go wash your face, go wash your face", I took off to - go wash my face!  I still have no idea what was in that sprayer, and am only lucky that I didn't suffer the consequences of my own ineptitude. 

This story leads me to this article based on the idea that if it can happen to me, it can certainly happen to others.  Garden chemical safety is not difficult.  It does take some forethought and diligence on the part of the home gardener.  Here are some tips:

1.       Know your chemicals.  Read about them before you buy them.  Make sure the chemical is absolutely the one you need.  Ask yourself: "Is this the only method available to accomplish my task; will this product find its way into our ground water supply, and ultimately, into our drinking water, and; is this product environmentally friendly?" 

2.       Keep chemicals in their original containers if possible, and if you must put them into an application device, read number three below. 

3.       Label your chemical application device (e.g., garden sprayer).  List the name of the chemical, the date you bought it, the expiration date if the original container gave one, and the intended use of the chemical. 

4.       Know the name of the chemical (e.g., RoundUp), and the phone number of the poison control center.  Many chemical containers also give a Medical Information phone number as well as First Aid instructions. 

5.       Store chemicals according to manufacturer instruction.  Recommended storage temperatures vary by product.  Remember to store them in places inaccessible to children and pets.  A locked cabinet specific to garden chemical storage, away from the house, food, children, and pets is an excellent idea. 

6.       While using the product wear long sleeves, long pants, and gloves.  Use a mask if there is any concern about inhalation of the product.  Don't use the chemical when children and pets are around. 

7.       When you are finished with your task, wash your hands well, and launder your clothing promptly. 

8.       Read the label on the original container and dispose of excess chemical and the container as instructed.  If you don't have the original container (or it is unreadable) take the environmentally safe route - directly to a hazardous waste drop-off site.  Never pour a chemical down the drain or somewhere else where it might jeopardize our ground water supply. 

Below is a list of San Luis Obispo County Integrated Waste Management Authority (IWMA) sites where you can drop off hazardous waste:

Cold Canyon Landfill, Hwy 227, SLO, 549-8332, open Friday and Saturday
11:00 am - 3:00pm;

Chicago Grade Landfill, Hwy 41, Atascadero, 466-2985, open Saturday 11:00am - 3:00pm;

Morro Bay Waste Water Plant, 160 Atascadero Rd, Morro bay, open Saturday 11:00am - 3:00pm;

Nipomo Facility, 509 Southland, Nipomo, open Saturday 11:00am - 3:00pm;

Paso Robles Landfill, Hwy 46 East, Paso Robles, open Saturday 11:00am - 3:00pm.

These sites and other information are available at http://iw! 

9.       As we near the end of our active gardening season it is a great time to go through our supply of garden chemicals and check for expiration dates (which may vary among chemicals and suppliers), leaking containers, unknown contents, and accessibility to children and animals.  Dispose of chemicals only as labels instruct. 

10.   Finally, ask yourself: "is my garden problem serious enough for a serious chemical; do I need a weed-killing chemical, or can I pull those weeds by hand and apply a layer of weed-inhibiting mulch; do I need a chemical fertilizer, or can I be proactive by preparing my garden beds with natural soil amendments used to their best advantage, and; is my need for a 'perfect garden' outweighed by long term environmental consequences"?

Websites mentioned are sites outside of the
University of California domain.  No endorsement is intended of products, services or information, nor is criticism implied of similar sites that are not mentioned.  To simplify information, trade names of products and/or company names have been used.  No endorsement of named products and/or companies is intended, nor is criticism implied of similar products and/or companies which are not mentioned. 

University of California Cooperative Extension Master Gardener Volunteers can provide additional gardening information upon request .Call the San Luis Obispo office at 781-5939 on Mondays and Thursdays from 1 to 5 PM.  You may also call the Paso Robles office at 237-3100 on Wednesdays from 9 AM to 12 PM.  The San Luis Obispo Master Gardeners website is at  Questions can be e-mailed to: