fosamine ammonium (Krenite) Herbicide Profile 2/85
CHEMICAL NAME: Ammonium ethyl carbamoylphosphonate (56)
TRADE NAME(S): Krenite (56)
FORMULATION(S): Krenite brush control agent is a liquid containing
41.5% active ingredient (4 lb/gal). Krenite S
brush control agent has same active ingredient
content but includes a surfactant (56).
BASIC PRODUCER(S): E.I. du Pont de Nemours Co., Inc.
1007 Market St.
Wilmington, DE 19898
STATUS: General use
PRINCIPAL USES: Used as a foliar spray at rates of 1 1/2 to 3
gallons product (6 to 12 lb ai)/acre applied in late summer or early
fall for control and/or growth suppression of many woody species.
Susceptible treated plants normally fail to refoliate during the
growing season following treatment and subsequently die. Krenite may
be used on noncropland areas such as railroad, pipeline, utility and
highway rights-of-way, drainage ditchbanks, storage areas, industrial
plant sites and other similar areas including land adjacent to and
surrounding domestic water supply reservoirs, supply stations, lakes
and ponds. It is also used for field bindweed control in noncropland
Registered for control and growth suppression of blackberry, white
oak, water oak, red oak, loblolly pine, Virginia pine, sweet gum, sumac
and black locust; salmonberry, thimbleberry, vine maple, American
elder, Eastern white pine, multiflora rose, slippery elm,
tree-of-heaven, wild grape, wild plum and quaking aspen; partial
control and growth suppression of other brush plants such as red alder,
hawthorn, wild cherry, maple, white ash, black gum, hickory, willow,
sassafras, yellow poplar, elm, big leaf maple, choke cherry, persimmon,
red maple, sourwood and tulip tree (yellow poplar). It is also
registerd for control of field bindweed. It is being evaluated for
bracken (Pteridium sp.) and for selective use in forestry (58).
APPLICATION METHOD(S): As a foliar spray either by air or ground
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C3 H8 N O4 P (62)
MOLECULAR WEIGHT: 153.1 (62)
PHYSICAL STATE: White crystalline solid (pure compound) (31v)
ODOR: Negligible odor (pure compound (31v)
MELTING POINT: 175 C (pure compound) (31v)
VAPOR PRESSURE: 4 x 10-6 mmHg at 25 C (pure compound) (31v)
SOLUBILITY: 1.79 kg/kg water at 25 C (pure compound) (62)
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: NA
NIOSH RECOMMENDED LIMIT: NA
ACGIH RECOMMENDED LIMIT: NA
A. ACUTE TOXICITY
DERMAL: LD50 = >1,680 mg/kg (rabbit, "Krenite"); >5,000
mg/kg (rabbit, "Krenite" S) (31v).
"Krenite" - Not a primary skin irritant when
applied as 25% aqueous solutions to shaved, intact,
or abraded skin of guinea pigs; no evidence of
sensitization. Application of 50% aqueous
solutions caused reversible mild to moderate
irritation in rabbits (31v).
"Krenite" S - Not a primary skin irritant when
applied as 0.5 ml undiluted formulation to shaved,
intact, or abraded skin of rabbits (31v).
ORAL: LD50 = 24,400 mg/kg (non-fasted male rats,
"Krenite"); >7380 mg (guinea pigs, "Krenite");
>15,000 mg/kg (female beagles, "Krenite"); >5,000
mg/kg (fasted male and female rats, "Krenite" S) (31v).
INHALATION: LC50 = 56.6 mg/l a.i. (male rat, "Krenite"); >42
mg/l a.i. (female rat, "Krenite") (31v).
LC50 = 3.20 mg/l a.i. (male rat, "Krenite" S);
2.75 mg/l a.i. (female rat, "Krenite" S) (31v).
EYES: "Krenite" = Administration of 0.1 ml product to
the rabbit eye resulted in no evidence of eye
"Krenite" S - Caused mild to no corneal opacity
and temporary severe to moderate conjuctival
irritation in the unwashed rabbit eyes. Eyes
returned to normal within 3 days except one
unwashed and one washed eye, which had lingering
mild conjunctival redness, but were normal within
7 days (31v).
B. SUBACUTE AND CHRONIC TOXICITY:
90-day rat feeding study: Slight effects on kidneys of male rats at
5000-10,000 ppm, 1000 ppm no-effect level.
6-month dog feeding study: No nutritional, clinical hematological,
biochemical, urinary, or gross pathological evidence of toxicity in the
test dogs fed 10,000 ppm. Relative stomach weights were significantly
high at 10,000 ppm but were associated with no other clinical or gross
1-generation rat reproduction study: No reproductive effects seen at
5000 ppm, the highest level fed.
Teratogenicity studies: Not teratogenic or embryotoxic in rats at
10,000 ppm, the highest level fed.
Mutagenicity studies: Not mutagenic in Ames, CHO point mutation and
DNA repair (UDS) assays. Mutagenic in in vitro Cytogenetic assay, but
negative in in vivo Cytogenetic assay (31v).
IV. ENVIRONMENTAL CONSIDERATIONS
Safe to fish and wildlife (8b).
Bluegill sunfish LC50 (96-hr) is greater than 670 ppm (formulation)
Fathead Minnow LC50 (96-hr) is greater than 1000 ppm (formulation)
Rainbow Trout LC50 (96-hr) is greater than 1000 ppm (formulation)
Bobwhite Quail LD50 is greater than 10,000 mg/kg (formulation)
Mallard Duck LD50 is greater than 10,000 mg/kg (formulation)
In a 28-day (14C) fosamine ammonium bioaccumulation study in catfish,
accumulation factor (ratio of residues in fish to residues in water)
was less than 12 (J. Toxic. Environ. Health. 5:957-963, 1979) (31v).
Fast disappearance rate in soil; half-life of about 7-10 days (J. Ag. &
Food Chem. 27 (3) 564-571, 1979). No effects on soil microbes (Soil
Science 128, 23, 1979) (31v).
LC50 (96-hr) is: for bluegill 278 mg a.i. (as e.c.)/l; for rainbow trout
>415 mg a.i. (as e.c.)/l (62).
Behavior In Or On Soils
1. Adsorption and leaching characteristics in basic soil types: In
field soil studies (Florida, Delaware and Illinois) with
14C-labeled ammonium ethyl carbamoylphosphonate, because of
rapid degradation, there was very little or no downward movement
of ammonium ethyl carbamoylphosphonate or its degradation
2. Microbial breakdown: Rapidly decomposed by soil microorganisms.
Labortory biometer flask tests to evaluate microbial degradation
in the dark were run with 14C-carbamoyl labeled ammonium ethyl
carbamoylphosphonate at 4 and 20 ppm in two soil types. These
tests showed that evolved 14CO2 accounted for 45 to 75% of
original 14C after 90-day incubations. Reincorporation of 14C
was noted, particularly in field soils.
3. Loss from photodecomposition and/or volatilization: Separate
experiments which measure photodecomposition in water indicate
that both artificial and natural sunlight exposures have little
effect. Photosensitizers do not appear to accelerate the
4. Persistence in soils: Greenhouse soil disappearance test with
14C-labeled ammonium ethyl carbamoylphosphonate indicated about
a 10-day half life for the intact compound. Also, under field
conditions in Florida, Delaware and Illinois the half life for
the compound was about 1 week. In these field studies, the half
life for total 14C-activity was 2 to 6 months. Much of the
residual 14C was reincorporated into the soil organic matter,
e.g., a-humus, B-humus and soluble humin fractions.
Han, Jerry C.Y. and R.L. Krause. 1979. Microbial Activity in Soils
Treated with Fosamine Ammonium. Soil Science. 128:23-27.
Han, Jerry C.Y. 1979. Stability of (14C) Fosamine Ammonium in Water
and Soils. Agric. Food Chem. 27(3):564 (58).
V. EMERGENCY AND FIRST AID PROCEDURES
The chemical information provided below has been condensed
from original source documents, primarily from "Recognition and
Management of Pesticide Poisonings", 3rd ed. by Donald P. Morgan,
which have been footnoted. This information has been provided in
this form for your convenience and general guidance only. In
specific cases, further consultation and reference may be required
and is recommended. This information is not intended as a sub-
stitute for a more exhaustive review of the literature nor for the
judgement of a physician or other trained professional.
If poisoning is suspected, do not wait for symptoms to develop.
Contact a physician, the nearest hospital, or the nearest Poison
SYMPTOMS: No symptoms of human intoxication have been reported.
In small mammals mild diarrhea has been observed after repeated oral
SKIN CONTACT: Wash with plenty of soap and water (31v).
EYE CONTACT: Flush with plenty of water (31v).
VI. FIRE AND EXPLOSION INFORMATION
GENERAL: Non-flammable (Krenite) (31w).
FIRE FIGHTING/EXTINGUISHER TYPE: Conventional methods (water spray,
CO2, foam, dry chemical). Use self-contained breathing apparatus
Not normally used in combination with other pesticides. Somewhat
corrosive to brass or copper sprayer parts (58).
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: Aqueous formulations and spray tank solutions
are stable. Subject to decomposition in dilute solution (5 ppm) under
acid conditions (58).
Keep out of reach of children. Do not contaminate water, food, or
feed by storage. Keep from contact with fertilizer, insecticides,
fungicides, and seed. May irritate eyes, nose, throat, and skin.
Avoid breathing spray or mist. Avoid contact with skin, eyes, and
clothing. Do not use on food crops. Do not allow drift or spray mist
to contact desirable trees, shrubs, or other plants, as injury may
result. Do not apply directly to water. Do not contaminate water by
cleaning of equipment or disposal of wastes (31v).
IX. PROCEDURES FOR SPILLS AND LEAKS
IN CASE OF EMERGENCY, CALL, DAY OR NIGHT
PESTICIDE TEAM SAFETY NETWORK/CHEMTREC
Clean up promptly; do not flush with water. Absorb liquid spills
with earth or sand and pick up by most effective means (Krenite) (31w).
X. LITERATURE CITED
8b. Thomson, W.T. 1981. Agricultural chemicals - book 2:
herbicides. Revised ed. Thomson Publications, Fresno, CA.
31v. E. I. du Pont de Nemours and Company, Inc., Biochemicals Department.
1983. Technical data sheet for fosamine ammonium.
31w. E. I. du Pont de Nemours and Company, Inc., Biochemicals Department.
1980. Material safety data sheet for Krenite brush control
agent. Wilmington, DE.
56. Farm Chemicals Handbook, 70th ed. 1984. R. T. Meister, G. L.
Berg, C. Sine, S. Meister, and J. Poplyk, eds. Meister
Publishing Co., Willoughby, OH.
58. Weed Science Society of America, Herbicide Handbook Committee.
1983. Herbicide handbook of the weed science society of
America, 5th ed. Weed Science Society of America, Champaign,
IL. 515 pp.
62. The Pesticide Manual: A World Compendium, 7th ed. 1983. C.R.
Worthing, ed. The British Crop Protection Council, Croydon,
England. 695 pp.