Ractopamine hydrochloride

Ractopamine hydrochloride	Last updated: 16/09/2025
(Also known as: ractopamine HCl)

GENERAL INFORMATION

Description

A substance often used as a feed additive to promote performance. Now banned in many countries including the EU & china.

Examples of veterinary uses

Once used for its economic and performance benefits - increasing rate of body mass gain, improving feed efficiency, and increasing carcass leanness

Examples of species treated

Pigs; Cattle; Turkeys

Approval status

VMR 2013/2033 approval status (GB/UK)

Not approved

EU Regulatory approval status

Not approved

Chemical structure

Isomerism

The technical material is a mixture of 4 stereoisomers. It is the RR-form of ractopamine is the most biologically active isomer.

Chemical formula

C₁₈H₂₄ClNO₃

Canonical SMILES

CC(CCC1=CC=C(C=C1)O)NCC(C2=CC=C(C=C2)O)O.Cl

Isomeric SMILES

International Chemical Identifier key (InChIKey)

JHGSLSLUFMZUMK-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C18H23NO3.ClH/c1-13(2-3-14-4-8-16(20)9-5-14)19-12-18(22)15-6-10-17(21)11-7-15;/h4-11,13,18-22H,2-3,12H2,1H3;1H

2D structure diagram/image available?

Yes

General status

Veterinary substance type

Feed additive; Animal growth promotor

Substance groups

Phenethanolamine

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

A phenolethanolamine beta-adrenoceptor agonist

Molecular targets

[Beta-adrenergic receptor, Agonist]

CAS RN

90274-24-1

EC number

415-170-5

CIPAC number

US EPA chemical code

PubChem CID

14010333

Therapeutic Class

ATCvet Code

None allocated

Controlled Drug?

Regulation 37/2010 MRL Classification

Banned in the EU & UK

Molecular mass

337.8

PIN (Preferred Identification Name)

IUPAC name

4-[3-[[2-hydroxy-2-(4-hydroxyphenyl)ethyl]amino]butyl]phenol;hydrochloride

CAS name

Forever chemical

Other status information

Relevant Environmental Water Quality Standards

Physical state

Related substances & organisms

ractopamine

Commercial

Property

Value

Availability status

Current; Banned in many countries

Introduction & key dates

1980s, discovered; 1999, first approvals USA

Example manufacturers & suppliers of products using this active now or historically

Huvepharma
Zoetis Inc.
Elanco Animal Health

Example products using this active

Optigrid 45
Paylean
Actogain
Topmax

Formulation and application details

Typically formulated as a Type A medicated substance which is a concentrated premix designed to be incorporated into animal feed

Commercial production

The commercial production of ractopamine hydrochloride typically begins with the synthesis of its core structure via reductive amination, using precursors like raspberry ketone and octopamine. Under controlled conditions, these compounds undergo microwave-assisted hydrogenation in the presence of heterogeneous catalysts such as platinum or rhodium on carbon, which significantly accelerates the reaction and improves selectivity toward the desired beta-adrenergic agonist. Once the ractopamine free base is formed, it is purified and then crystallised to achieve high purity. The final step involves acidification with hydrochloric acid, converting the free base into its hydrochloride salt.

Impact on climate of production and use

Published GHG data is not available for most pharmaceuticals. However, according to industry, global averages suggest producing 1 kg of a typical active pharmaceutical ingredient can range from 10 to 100 kg CO₂e for small molecule drugs and potentially up to 1000 kg CO₂e for complex biologicals such as vaccines, depending on the drug type, its formulation, complexity of synthesis, solvent recovery, and energy sources used.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

Solubility - In water at 20 °C (mg l⁻¹)

31000

High

Solubility - In organic solvents at 20 °C (mg l⁻¹)

Melting point (°C)

163.9

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

Octanol-water partition coefficient at pH 7, 20 °C

Log P

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

Henry's law constant at 25 °C (Pa m³ mol⁻¹)

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

Maximum UV-vis absorption L mol⁻¹ cm⁻¹

Max absorbance at 225.8nm=463 and 277.6nm=93

Surface tension (mN m⁻¹)

Refractive Index

Environmental release

Substance may enter the environment via the urine of treated animals or by leaching from spilt medicated feed.

Degradation

Property

Value

Source; quality score; and other information

Interpretation

Soil degradation (days) (aerobic)

DT₅₀ (typical)

1.1

Non-persistent

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

Note

Manure DT₅₀ (days)

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Note

Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7

Value

0.009

Non-persistent

Note

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

Sediment phase only DT₅₀ (days)

Air degradation

As this parameter is not normally measured directly, a surrogate measure is used: ‘Photochemical oxidative DT₅₀’. Where data is available, this can be found in the Fate Indices section below.

Decay in stored produce DT₅₀

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d (mL g⁻¹)

26.7

Slightly mobile

K_oc (mL g⁻¹)

2265

Notes and range

USEPA data: K_d range 14.5-36.0 mL g⁻¹, K_oc range 2007-2698 mL g⁻¹, Soils=3

Freundlich

K_f (mL g⁻¹)

K_foc (mL g⁻¹)

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.03

Calculated

Low leachability

Bio-concentration factor

BCF (l kg⁻¹)

6.3

Low potential

CT₅₀ (days)

Known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

Mammals - Short term dietary NOEL

(mg kg⁻¹)

(ppm diet)

Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)

Birds - Acute LD₅₀ (mg kg⁻¹)

Birds - Short term dietary (LC₅₀/LD₅₀)

Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)

Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹ dw soil)

Earthworms - Chronic NOEC, reproduction (mg kg⁻¹ dw soil)

Soil micro-organisms

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

Vegetative vigour ER₅₀ (g ha⁻¹)

Seedling emergence ER₅₀ (g ha⁻¹)

Honeybees (Apis spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Chronic

Notes

Bumblebees (Bombus spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Mason bees (Osmia spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Other bee species (1)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Other bee species (2)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Beneficial insects (Ladybirds)

Beneficial insects (Lacewings)

Beneficial insects (Parasitic wasps)

Beneficial insects (Predatory mites)

Beneficial insects (Ground beetles)

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

5.44

Lepomis macrochirus

Moderate

Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)

Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)

34.5

Daphnia magna

Low

Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)

Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)

Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)

Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)

Aquatic Plants (free-floating, fonds growth, fresh) - 7 day (mg l⁻¹)

Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)

Algae - Acute (growth rate, fresh; mg l⁻¹) (EC₅₀)

> 101.2

Raphidocelis subcapitata

Low

Algae - Chronic (growth rate, fresh; mg l⁻¹)

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves

HUMAN HEALTH AND PROTECTION

General

Property

Value

Source; quality score; and other information

Interpretation

Threshold of Toxicological Concern (Cramer Class)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 2.8

Rat 4 hr

Other Mammal toxicity endpoints

Intraperitoneal LD₅₀ = 367 mg kg⁻¹

Rat

ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)

ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)

AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)

AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

Exposure Routes

Public

Occupational

Mammalian dose elimination route and rate

Rapidly emininated via the urine

Health issues

Specific human health issues (hazard-based)

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

May cause skeletal muscle tremors and behavioural changes
May cause cardiovascular effects

Handling issues

Property

Value and interpretation

General

Not compatible with oxidising agents
Will produce irritating and toxic gases if heated to decomposition
Corrosive

CLP classification 2013

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

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Name

English

ractopamine hydrochloride

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Record last updated:	16/09/2025
Contact:	aeru@herts.ac.uk
Please cite as:	Lewis, K.A., Tzilivakis, J., Warner, D. and Green, A. (2016) An international database for pesticide risk assessments and management. Human and Ecological Risk Assessment: An International Journal, 22(4), 1050-1064. DOI: 10.1080/10807039.2015.1133242