Pest Management Home Page
Agriculture, Natural Resources, & Community Development
Home Page
Patrick Porter
IPM Specialist
WVU Extension Service
Last updated 3/25/98
This document lists the acute (short term) toxicity of many insecticides available through retail outlets or mail order companies. It is presented to allow insecticide users to make informed choices when buying pest control products. Table salt, DDT, and chlordane have been added to the list for comparison purposes.
All pesticides can be toxic, but some are far more toxic than others. Readers will notice that "organic" insecticides (those of botanical origin) are still quite toxic and should not be considered safe. This was well stated by Rick Weinzierl and Tess Henn in the Handbook of IPM for Turf and Ornamentals (1994), "Natural compounds are not inherently less toxic to humans than synthetic ones. Some of the most deadly, fast-acting toxins and some potent carcinogens occur naturally. Despite the claims presented in some advertising materials, "natural" does not necessarily mean safe or nontoxic, and it certainly does not mean nonchemical.."
All pesticides go through thorough toxicity testing before being registered by the Environmental Protection Agency. Acute (short-term) toxicity is measured as the amount of toxin that kills 50% of laboratory animals in a test. This quantity is abbreviated as an LD50 value (Lethal Dose 50%). The following table presents dermal (through the skin) and oral (through the mouth) LD50 values. These values are usually expressed as milligrams of toxin per kilogram of body weight (mg/kg). Smaller values indicate a more toxic product.
To make these quantities more relevant, two additional colums have been added: "Dermal dose to kill a 150 lb. person" and "Oral dose to kill a 150 lb. person". These are the approximate number of pounds of active ingredient that would kill half of the150 lb. individuals in a test. These values are extrapolated from the LD50 data and assume lab animals and humans have a similar response to the product. Again, smaller values indicate a more toxic product.
Example of how one might use this table
Let us assume a gardener wants to control Colorado potato beetle. He or she has several insecticides available, including Thiodan, Bacillus thuringiensis variety san diego (sold as M-ONE), or Sevin. Thiodan (endosulfan) has a dermal LD 50 value of 74, or in other words, 0.011 pounds for a person weighing 150 pounds. Bacillus thuringiensis variety san diego is nontoxic. Sevin (carbaryl) has a dermal LD 50 value of 4,000, or 0.600 pounds for a 150 pound person. From an acute toxicity standpoint, Bacillus thuringiensis is the safest product. Of the two synthetic pesticides, Sevin is much safer than Thiodan. In fact, Sevin is 54 times safer than Thiodan (4,000/74 = 54). A gardener who is concerned about acute toxicity might use either Bacillus thuringiensis or Sevin, but would probably not choose to use Thiodan for controlling Colorado potato beetle.
County Extension Agents can help explain this table and help you choose pest control products.
Table 1. Toxicity of some common household and garden insecticides (3/25/98)
Active Ingredient (Commercial Name) |
Class |
Dermal LD50 (mg/kg) |
Dermal dose to kill a 150 lb. person (lbs.) |
Oral LD50 (mg/kg) |
Oral dose to kill a 150 lb. person (lbs.) |
| abamectin (AGRI- MEK) | antibiotic | 2,000 |
0.300 |
4,200 |
0.630 |
| acephate (Orthene) | organophosphate | 2,000 |
0.300 |
866 |
0.130 |
| azadirachtin (neem) | botanical | _ |
_ |
5,000 |
0.750 |
| Bacillus thuringiensis | biological | _ |
_ |
_ |
_ |
| Bacillus popilliae | biological | _ |
_ |
non-toxic |
non-toxic |
| Beauvaria bassiana | biological | _ |
_ |
_ |
_ |
| boric acid | inorganic salt | _ |
_ |
10,000 |
1.500 |
| carbaryl (Sevin ) | carbamate | 4,000 |
0.600 |
850 |
0.128 |
| chlordane | organochlorine | 580 |
0.087 |
283 |
0.042 |
| chlorpyrifos (Dursban) | organophosphate | 2,000 |
0.300 |
135 |
0.020 |
| cryolite, Kryocide | inorganic | _ |
_ |
10,000 |
1.500 |
| cucurbitacin (Slam) | biological | _ |
_ |
_ |
_ |
| cypermethrin (Vikor etc.) | pyrethroid | 2,000 |
0.300 |
247 |
0.037 |
| d-Limonene | botanical | _ |
_ |
5,000 |
0.750 |
| DDT | organochlorine | 1,931 |
0.290 |
87 |
0.013 |
| deet (in insect repellents) | repellent | _ |
_ |
2,000 |
0.300 |
| diazinon | organophosphate | 379 |
0.057 |
66 |
0.010 |
| dichlorvos (Vapona, DDVP) | organophosphate | 59 |
0.009 |
25 |
0.004 |
| dicofol (Kelthane) | organochlorine | 4,000 |
0.600 |
575 |
0.086 |
| diflubenzuron (Dimilin) | growth regulator | _ |
_ |
4,640 |
0.696 |
| dimethoate (Cygon) | organophosphate | 150 |
0.023 |
250 |
0.038 |
| endosulfan (Thiodan) | organochlorine | 74 |
0.011 |
18 |
0.003 |
| fenoxycarb | growth regulator | 2,000 |
0.300 |
10,000 |
1.500 |
| imidacloprid (Grub- X, Merit) | chloronicotinyl | 5,000 |
0.750 |
450 |
0.068 |
| imidacloprid (Provado, Admire) | chloronicotinyl | 5,000 |
0.750 |
450 |
0.068 |
| linalool | botanical | 5,976 |
0.896 |
2,810 |
0.422 |
| lindane | organochlorine | 500 |
0.075 |
76 |
0.011 |
| malathion | organophosphate | 4,100 |
0.615 |
1,842 |
0.276 |
| methoprene (Precor, Altosid) | growth regulator | 3,000 |
0.450 |
34,600 |
5.190 |
| methoxychlor | organochlorine | 2,820 |
0.423 |
5,000 |
0.750 |
| nicotine (black leaf 40) | botanical | 50 |
0.008 |
55 |
0.008 |
| Nosema locustae | biological | _ |
_ |
_ |
_ |
| permethrin (Ambush, Pounce) | pyrethroid | 2,000 |
0.300 |
2,200 |
0.330 |
| permethrin (Intercept HG Products) | pyrethroid | 5,000 |
0.750 |
4,810 |
0.722 |
| piperonyl butoxide | synergist | 7,500 |
1.125 |
7,500 |
1.125 |
| propoxur (Baygon) | carbamate | 1,000 |
0.150 |
95 |
0.014 |
| pyrethrins, pyrethrum | botanical | 1,800 |
0.270 |
1,350 |
0.203 |
| resmethrin | pyrethroid | 3,000 |
0.450 |
2,500 |
0.375 |
| rotenone liquid | botanical | 1,000 |
0.150 |
60 |
0.009 |
| ryania powder | botanical | 4,000 |
0.600 |
975 |
0.146 |
| sabadilla | botanical | _ |
_ |
4,000 |
0.600 |
| salt, table | _ |
_ |
3,000 |
0.450 |
|
| insecticidal soap | soap | _ |
_ |
16,500 |
2.475 |
| ultra- fine Oil | oil | _ |
_ |
_ |
_ |
Note that some products have a wide range of LD50 values due to formulation and test
animal species differences. When LD50 values differed between references, those presented
in Ware (1994) were reported.
Sources and recommended reading:
Ware, G. W. 1994, The Pesticide Book, Thompson Publications, Fresno, California.
Farm Chemicals Handbook 1996, Meister Publishing, Willoughby, Ohio.
Weinzierl, R. W. and T. Henn. 1994. Botanical Insecticides and Insecticidal Soaps. In: Handbook of Integrated Pest Management for Turf and Ornamentals. CRC Press (Lewis Publishers), Boca Raton, Florida.
