(Also known as: terramycin; oxytracyl; oxytetrin; terramitsin; oxitetracycline; crop antibiotic)
SUMMARY
Hazard alerts
The following alerts are based on the data in the tables below. An absence of an alert does not imply the substance has no implications for human health, biodiversity or the environment but just that we do not have the data to form a judgement. These hazard alerts do not take account of usage patterns or exposure, thus do not represent risk.
Environmental fate
Ecotoxicity
Human health
Environmental fate Moderate alert: Potential for particle bound transport: Medium
Human health Moderate alert: Reproduction/development effects
GENERAL INFORMATION
Description
A bactericide used to control bacteria, fungi and mycoplasma-like organisms in fruit and turf, also used in veterinary products and for aquaculture
GB regulatory status
GB COPR regulatory status
Not approved
Date COPR inclusion expires
Not applicable
GB LERAP status
No UK approval for use as a plant protection agent
EC Regulation 1107/2009 (repealing 91/414)
EC Regulation 1107/2009 status
Not approved
Dossier rapporteur/co-rapporteur
Not applicable
Date EC 1107/2009 inclusion expires
Not applicable
EU Candidate for substitution (CfS)
Not applicable
Listed in EU database
Yes as oxytetracycline
Approved for use (✓) under EC 1107/2009 in the following EU Member States
ATAustria
BEBelgium
BGBulgaria
CYCyprus
CZCzech Republic
DEGermany
DKDenmark
EEEstonia
ELGreece
ESSpain
FIFinland
FRFrance
HRCroatia
HUHungary
IEIreland
ITItaly
LTLithuania
LULuxembourg
LVLatvia
MTMalta
NLNetherlands
PLPoland
PTPortugal
RORomania
SESweden
SISlovenia
SKSlovakia
Approved for use (✓) under EC 1107/2009 by Mutual Recognition of Authorisation and/or national regulations in the following EEA countries
ISIceland
NONorway
Additional information
Also used in
Northern Ireland
Chemical structure
Isomerism
Oxytetracycline hydrochloride exhibits stereoisomerism, particularly epimerism and tautomerism, due to its multiple chiral centres and functional groups capable of rearrangement. The molecule contains several asymmetric carbon atoms, notably at positions 4, 4a, 5, 5a, 6, and 12a, which allow for the formation of diastereomers. One common isomeric form is 4-epioxytetracycline, which arises from inversion at the C-4 position and can occur spontaneously in aqueous solutions, especially under acidic conditions. Additionally, oxytetracycline undergoes tautomerism involving its keto and enol groups, particularly in the diketone and hydroxyl regions of the tetracycline ring system. Only one stereoisomer is used therapeutically.
1945, discovered; 1949, marketing launch; 1950s, first vet approvals
Example manufacturers & suppliers of products using this active now or historically
Syngenta
Norbrook Laboratories Ltd
MSD Animal Health Ltd
Example products using this active
Mycoshield
Cuprimicina Agrıcola
Cuprimicın 100
Mycoject
Alamycin LA Injection
Engemycin Cutaneous Spray
Alamycin Aerosol Cutaneous Spray
Formulation and application details
Supplied as a water soluble powder for preparation as injection when used as a veterinary product. For crop protection it is used as a foliar spray
Commercial production
Oxytetracycline hydrochloride is produced through a multi-stage process that begins with fermentation using Streptomyces rimosus, a soil-dwelling bacterium known for its ability to biosynthesise tetracycline antibiotics. During fermentation, the organism converts simple carbon sources into oxytetracycline via a polyketide synthase pathway, forming a tetracyclic ring structure through sequential condensation and cyclisation reactions. After fermentation, the broth is filtered to isolate crude oxytetracycline, which is then purified through solvent extraction and crystallisation. To form the hydrochloride salt, hydrogen chloride is introduced, often in a solvent system like n-butanol and isopropanol, facilitating salt formation and recrystallisation into a stable dihydrate form.
Impact on climate of production and use
As microbial-based products tend to use fermentation-based production processes rather than chemical synthesis, they typically have a lower fossil fuel input in formulation and active ingredient creation, and also have reduced downstream emissions due to biodegradability and minimal soil disruption, their life-cycle GHG emissions are expected to be low. Whilst hard and precise data is not available, broad estimates suggest that typically emissions are likely to be below 5 kg CO₂e/kg.
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C (mg l⁻¹)
6900
R4 R = Peer reviewed scientific publications 4 = Verified data
High
Solubility - In organic solvents at 20 °C (mg l⁻¹)
-
-
-
Melting point (°C)
121
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
-
Boiling point (°C)
-
-
-
Degradation point (°C)
-
-
-
Flashpoint (°C)
-
-
-
Octanol-water partition coefficient at pH 7, 20 °C
P
6.03 X 10-02
Calculated
-
Log P
-1.22
R4 R = Peer reviewed scientific publications 4 = Verified data
Low
Fat solubility of residues
Solubility
-
-
-
Data type
-
-
-
Density (g ml⁻¹)
1.63
Q2 Q = Miscellaneous data from online sources 2 = Unverified data of unknown source
-
Dissociation constant pKa) at 25 °C
4.5
R4 R = Peer reviewed scientific publications 4 = Verified data
-
Weak acid
Vapour pressure at 20 °C (mPa)
1.29 X 10-19
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
at 25 °C
Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)
1.72 X 10-20
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
at 25 °C
Non-volatile
Volatilisation as max % of applied dose lost
From plant surface
-
-
-
From soil surface
-
-
-
Maximum UV-vis absorption L mol⁻¹ cm⁻¹
-
-
-
Surface tension (mN m⁻¹)
-
-
-
Degradation
Property
Value
Source; quality score; and other information
Interpretation
General biodegradability
-
Soil degradation (days) (aerobic)
DT₅₀ (typical)
18
R4 R = Peer reviewed scientific publications 4 = Verified data
Non-persistent
DT₅₀ (lab at 20 °C)
21
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source
Non-persistent
DT₅₀ (field)
-
-
-
DT₉₀ (lab at 20 °C)
-
-
-
DT₉₀ (field)
-
-
-
DT₅₀ modelling endpoint
-
-
-
Note
Literature estimates give DT₅₀ 1 to 10 wks
Dissipation rate RL₅₀ (days) on plant matrix
Value
-
-
-
Note
-
Dissipation rate RL₅₀ (days) on and in plant matrix
Value
-
-
-
Note
-
Aqueous photolysis DT₅₀ (days) at pH 7
Value
-
-
-
Note
-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7
Value
-
-
-
Note
-
Water-sediment DT₅₀ (days)
-
-
-
Water phase only DT₅₀ (days)
9
R3 R = Peer reviewed scientific publications 3 = Unverified data of known source
Moderately fast
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
Kd (mL g⁻¹)
698
R4 R = Peer reviewed scientific publications 4 = Verified data
Non-mobile
Koc (mL g⁻¹)
52875
Notes and range
Literature data: Kd range 417-1626 mL g⁻¹, Koc range 27792-93317 mL g⁻¹, soils=4; Other Literature data 27792-93317 generally quoted for tetracyclines (R4)
Freundlich
Kf (mL g⁻¹)
-
-
-
Kfoc (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
-0.96
Calculated
Low leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
5.35 X 10-03
Calculated
-
Note
Estimated concentrations of chemicals with Koc values greater than 9995 ml g⁻¹ are beyond the scope of the regression data used in SCI-GROW development. If there are concerns for such chemicals, a higher tier groundwater exposure assessment should be considered, regardless of the concentration returned by SCI-GROW
Potential for particle bound transport index
Medium
Calculated
-
Potential for loss via drain flow
Non-mobile
Calculated
-
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk
-
-
-
Bio-concentration factor
BCF (l kg⁻¹)
0.6
J2 J = Pesticide Action Network database (click here ) 2 = Unverified data of unknown source
Mollusca
Low potential
CT₅₀ (days)
Not available
-
Known metabolites
None
ECOTOXICOLOGY
Terrestrial ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
> 4800
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
R4 R = Peer reviewed scientific publications 4 = Verified data
Low
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)
-
-
-
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)
100
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source
Moderate
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)
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
Environmental fate
