What are inert or other ingredients?
Pesticide products contain both active ingredients and inert ingredients. Inert ingredients are also called
other
ingredients.1
Active ingredients are the chemicals in the product that are actually meant to kill or repel the pest. The
other
ingredients in
the product play some other role besides controlling the pest.2
Although
other ingredients are sometimes called "inert" the
name does not mean that they are non-toxic.1 See the text box on
Pesticide Products.
Active and other ingredients together make up a formulated pesticide product. Manufacturers must list the
names
of all active
ingredients and the percentage of the product that is made up of other ingredients on the product label, but
they do not
usually have to list the names of other ingredients.3
Other ingredients are used in pesticide products for a variety of reasons, including:2
- To stabilize the product and extend shelf-life
- To help the pesticide stick to surfaces like leaves and soil
- To help the pesticide spread over surfaces
- To help the pesticide dissolve in water
- To prevent caking or foaming
- Ease of application (prevent clogging, product uniformity)
- To make ingredients compatible
- Drift control
Why are the other ingredients not listed on the product label?
Other ingredients are not required by law to be specifically listed on the label. Full pesticide product
formulations must be
provided to the EPA, but they are considered trade secrets or confidential business information.3 Therefore,
the manufacturers
do not have to list them.
There are some exceptions. For example, products that contain greater than 0.1% sodium nitrate or greater
than
10% xylene
range aromatic solvents, xylene, or petroleum distillates must list these ingredients on the label.2
If a pesticide product contains only ingredients from a special list maintained by the U.S. EPA and its
labeling
meets certain requirements,
manufacturers do not have to register that product with the U.S. EPA.4
They
may have to register it with individual
states, however. These products must list all active and other ingredients on their labels.4
How toxic are other ingredients?
Other ingredients range from low in toxicity to highly toxic. See the
text box on Dose Response.
The toxicity of formulated pesticide products
depends on both the active and other ingredients. The U.S. EPA
evaluates product toxicity during registration and displays the toxicity
on the label in the form of a signal word.6 See the
Signal Words
Fact Sheet.
See the text boxes on Toxicity
Category and
LD50/LC50.
LD50/LC50: A
common
measure of acute toxicity is the lethal dose (LD50) or
lethal concentration (LC50) that causes death (resulting
from a single or limited exposure) in 50 percent of the treated
animals. LD50 is generally expressed as the dose in
milligrams (mg) of chemical per kilogram (kg) of body
weight. LC50 is often expressed as mg of chemical per
volume (e.g., liter (L)) of medium (i.e., air or water) the organism
is exposed to. Chemicals are considered highly toxic when the
LD50/LC50 is small and practically non-toxic
when the value is large. However, the LD50/LC50
does not reflect any effects from long-term exposure (i.e., cancer,
birth defects or reproductive toxicity) that may occur at levels below
those that cause death.
TOXICITY CATEGORY (Signal Word)2
|
High Toxicity
(DANGER/Danger-Poison)
Category I |
Moderate Toxicity
(WARNING)
Category II |
Low Toxicity
(CAUTION)
Category III |
Very Low Toxicity
(Optional Signal Word = CAUTION)
Category IV |
| Acute Oral LD50 |
Up to and including 50 mg/kg
(≤ 50 mg/kg) |
Greater than 50 through 500 mg/kg
(>50-500 mg/kg) |
Greater than 500 through 5000 mg/kg
(>500-5000 mg/kg) |
Greater than 5000 mg/kg
(>5000 mg/kg) |
| Inhalation LC50 |
Up to and including 0.05 mg/L
(≤0.05 mg/L) |
Greater than 0.05 through 0.5 mg/L
(>0.05-0.5 mg/L) |
Greater than 0.5 through 2.0 mg/L
(>0.5-2.0 mg/L) |
Greater than 2.0 mg/L
(>2.0 mg/L) |
| Dermal LD50 |
Up to and including 200 mg/kg
(≤200 mg/kg) |
Greater than 200 through 2000 mg/kg
(>200-2000 mg/kg) |
Greater than 2000 through 5000 mg/kg
(>2000-5000 mg/kg) |
Greater than 5000 mg/kg
(>5000 mg/kg) |
| Primary Eye Irritation |
Corrosive (irreversible destruction of
ocular tissue) or corneal involvement or
irritation persisting for more than 21 days |
Corneal involvement or other
eye irritation clearing in 8 -
21 days |
Corneal involvement or other
eye irritation clearing in 7
days or less |
Minimal effects clearing in less than 24 hours |
| Primary Skin Irritation |
Corrosive (tissue destruction into the
dermis and/or scarring) |
Severe irritation at 72 hours
(severe erythema or edema) |
Moderate irritation at 72
hours (moderate erythema) |
Mild or slight irritation at
72 hours (no irritation or
erythema) |
A pesticide product is a commercially
available mixture of chemicals used to kill, repel, or otherwise
control one or more specific pest. The product consists
of the active ingredient(s) and the inert ingredient(s).
Active ingredients are the chemicals that are actually effective
against the pest. The rest of the product is composed
of an inert ingredient(s). The percentage of total
inert ingredient(s) (which can range from 0 to 99.9%) is
listed on the product label.
Effects of inert ingredients on human
health and the environment depend on how much chemical
is present, the length and frequency of exposure, and
route of exposure. Effects also depend on the health of a
person and/or certain environmental factors.
Where can I find a list of approved other ingredients?
EPA maintains several lists of inert ingredients. There are separate
lists for non-food uses and food
uses.
The most up-to-date list of other ingredients that can be used in pesticides with food
uses can be found in the Electronic Code of Federal Regulations,
Title 40 Part 180, Tolerances and Exemptions for Pesticide Chemical
Residues in Food. Any other ingredient approved for food use
can be used in a non-food pesticide product.7
Minimum-risk pesticide ingredients are found in the FIFRA Section
25(b) list and an additional list, the 4(a)
list. Some other
ingredients can be used as active ingredients but in order for the
product to qualify as a minimum-risk product, the other ingredients
must also be listed in the FIFRA Section 25(b) List.4
Other ingredients that may be used in products for organic agriculture can be found on the U.S. Department of
Agriculture's
National Organic Program Inert Ingredients List.
The U.S. EPA also provides guidance on the registration pages of Office of Pesticide Programs website for
manufacturers wishing
to add a new other ingredient to any of these lists.
How can I find out what other ingredients are in my pesticide product?
Manufacturers will sometimes provide some information on other ingredients on the product Safety Data
Sheet
(SDS). Freedom of Information Act (FOIA) requests can be submitted to the U.S. EPA for information on
other
ingredients.
The US EPA may consult with the manufacturer before deciding whether to provide the information.3
Pesticide companies may disclose the other ingredients in their products to medical professionals needing
the
information
to treat pesticide poisoning cases. Medical staff may be asked to sign a statement that the information
will be
kept confidential.
