1996-1997 New England Apple Pest Management Guide

 ACUTE TOXICITY OF PESTICIDES

Pesticide hazard to warm-blooded animals, including humans, is usually determined in relation to the way it enters the body. Methods of entry include the respiratory system, digestive system and skin. The greatest hazard is by pesticide entry via the respiratory system. Pesticide toxicity by this route is not much different from that of intravenous injection because membranes of the lungs that separate air from blood are extremely thin; therefore absorption is very rapid (this is also true for the eyes). Absorption through the digestive tract is the next most hazardous avenue for poisoning. The skin provides the most effective barrier against pesticides. However, there is considerable variation in the rate of penetration through the skin by different materials and formulations.

The greatest hazard from pesticides occurs while mixing and applying, not from accidental ingestion. However, when spraying, many airborne spray particles are trapped in the secretions of the upper respiratory tract and swallowed, thereby providing exposure by ingestion. Assuming that the person applying the pesticide takes adequate precaution (respirator, goggles, etc.) to prevent this type of exposure, dermal toxicity is probably a more realistic index of occupational hazard than oral toxicity.

DANGER - POISON, WARNING, CAUTION:

One of these "signal words" appears on the label of every pesticide. Acute (or immediate, single dose) toxicity is reported as an LD50 value. See Table 8 for Acute Toxicity Ratings of some apple pesticides. The LD50 for a chemical is the dose which has been found in controlled experiments to kill 50% of a large number of test animals. The LD50 dose is usually expressed as the number of milligrams (mg) of pure active ingredient per kilogram (kg) body weight of the test animals. The lower the LD50, the more toxic the chemical. Because the LD50 is based on animal tests and does not account for individual sensitivity, it does not necessarily represent the toxic dose for an individual human. The LD50 of a chemical gives no information on the possible long term health effects from repeated exposure at low levels.

In addition to oral or dermal acute toxicity, a pesticide may also carry the DANGER - POISON, or WARNING signal words because of other potential hazards, such as inhalation toxicity or the ability to cause severe eye or skin damage.

Table 9. Acute Toxicity of Apple Pesticides.


LD50 for test animals

(mg technical chemical

per kg body weight)


LD50 for test animals

(mg technical chemical

per kg body weight)


Chemical

Oral

Dermal


Chemical

Oral

Dermal


azadirachtin (Align)

>5,000

>2,000


methomyl (Lannate)

17

5880


azinphosmethyl (Guthion)

4

150-200


methoxychlor

6000

---


Bacillus thuringiensis toxin

nontoxic


methyl parathion encapsulated(PenncapM)

>600

>5,400


basic copper sulfate(Basicop)

30

---


metiram (Polyram)

>6,810

>2,000


benomyl (Benlate)

>10,000

>10,000


myclobutanil (Nova)

1600

>5,000


captan

9,000

---1


NAA (Fruitone-N, K-Salt Fruit Fix)

1000

---


carbaryl (Sevin)

246

---


NAD (Amid-thin)

1690

>2,000


chlorophacinone (Rozol)

3

---


napropamide (Devrinol)

>500

---


chlorpyrifos (Lorsban)

96-270

2,000


norflurazon (Solicam)

>8,000

>20,000


clofentezine (Apollo)

>3,200

---


oil (refined petroleum distillate)

>15,000

>5,000

copper hydroxide

1,000

---

oryzalin (Surflan)

>10,000

---


copper oxychloride (COCS)

1,131

>2,000


oxamyl (Vydate)

5

2960


diazinon

1,250

>2,020


oxyfluorfen (Goal)

>5,000

>10,000


dichlobenil

(Casoron, Norosac)

>4,460

> 2000


oxythioquinox (Morestan)

1500

>5,000


dicofol (Kelthane)

570

5,000


paraquat (Gramoxone Extra)

150

---1


dimethoate (Digon)

235

400


pendimethalin (Prowl)

3956

>2,200


diphacinone (Ramik)

7

---


permethrin (Ambush, Pounce)

430-4,000

>4,000


disulfoton (Di-Syston)

2-12

3-16


phosmet (Imidan)

147-316

>4,640


diuron (Direx, Karmex)

>5,000

>5,000


promalin (Promalin)

4900

2900


dodine (Syllit)

1,000

6000


pronamide (Kerb)

8350

>3,160


endosulfan (Thiodan,Phaser)

160

359


pyrethrum

1500

>1800


esfenvalerate (Asana XL)

458

>2,000


pyrethrin & rotenone (Pyrellin E.C.)

1500

---


ethephon (Ethrel)

4,229

---


rotenone

132-1,500

---


fenarimol (Rubigan)

2,500

---


ryania

1200

---


fenbutatin-oxide (Vendex)

2,631

>2,000


sethoxydim (Poast)

3,200-3,500

>5,000


ferbam (Carbamate)

>17,000

---


simazine (Princep)

>5,000

>3,100


fluazifop-butyl (Fusilade)

3,382

---


streptomycin (Agri-Mycin)

9000

---2


formetanate HCl (Carzol)

21

>10,200


sulfosate (Touchdown)

750

>2001


fosetyl-Al (Aliette)

5,000

>2,000


sulfur

>5,000

>5,0002


glufosinate-ammonium(Rely)

2,000

4,000


terbacil (Sinbar)

5,000-7,500

---


glyphosate (Roundup)

>5,000

>5,000


thiophanate-methyl (Topsin-M)

7500

---


hexythiazox (Savey)

>5,000

>5,000


thiram

1000

>5,0001


imidacloprid (Provado)

450

>5,000


triadimefon (Bayleton)

1000

>5,000


insecticidal soap (M-Pede)

16,900

>5,000


triflumizole (Procure)

2230

2000


mancozeb

(Dithane, Penncozeb)

11,200

>15,000


zinc phosphide

46

---


maneb (Manex)

7,990

>5,000


ziram

1400

>6,000


metalaxyl (Ridomil)

669

>3,100


2,4-D (Weedar-64, Hi-Dep, Justice)

699

---


methidathion (Supracide)

44

6401




--- = unknown; > = greater than; 1 - Irritating to skin, mucous membranes; 2 - May cause skin reaction.

Note: Chemicals for which at least one formulation carries the DANGER signal word because of acute toxicity or some other hazard are in bold letters. Some formulations of the chemical may have a lower hazard signal word.

Adapted from: 1996 Farm Chemicals Handbook, Meister Publishing Company, editorial director C. Sine; Material Safety Data Sheets; and Pesticide Information Profiles, Web site EXTOXNET (Extension Toxicology Network)

 

On to EPA Definition of Inconsistent With Label

 

1996-1997 New England Apple Pest Management Guide