The following Pesticide Hazard Tricolour (PHT) 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. The alerts for Highly Hazardous Pesticides (HHPs) are based on applying the FAO/WHO (Type 1) and the PAN (Type II) criteria to PPDB data. Further details on the HHP indicators are given in the tables below. Neither the PHT nor the HHP hazard alerts take account of usage patterns or exposure, thus they do not represent risk.
PHT: Environmental fate
PHT: Ecotoxicity
PHT: Human health
Highly Hazardous Pesticide
Environmental fate Moderate alert: Drainflow: Moderately mobile
R01 Rule 1: Pesticide active ingredients that meet the criteria of classes Ia or Ib of the WHO Recommended Classification of Pesticides by Hazard; or those with a CLP classification of H330; or where Mammals acute oral LD₅₀ <= 50 mg kg⁻¹
;
R09 Rule 9: Pesticide active ingredients that have demonstrated a high aquatic toxicity (where acute ecotoxicity for fish, invertebrates or algae =< 0.1 mg l⁻¹)
]
Other status information
Some applications may be approved under national biocide regulations
Methylchloroisothiazolinone is supplied commercially as a liquid due to its instablity as a solid
Commercial production
Commercial manufacture of methylchloroisothiazolinone involves the controlled chlorination and cyclisation of appropriate thiol and amide containing precursors to form the isothiazolinone ring, followed by oxidation and purification steps to achieve the required active substance specification. It is almost always produced together with methylisothiazolinone (MIT) as a reaction mass (commonly the 3:1 CMIT/MIT mixture), because the manufacturing pathway inherently yields both species; downstream separation is not economically viable. The resulting preservative blend is then filtered, quality checked for active content, impurities, and stability.
Impact on climate of production and use
Methylchloroisothiazolinone has a carbon footprint driven almost entirely by its petrochemical, chlorine intensive manufacturing pathway. Although no public source provides a direct emission factor for MCIT itself, the closely related production of methylisothiazolinone (MIT) shows that isothiazolinone manufacture requires multiple high energy inorganic reagents (hydrochloric acid, ammonia, caustic soda, calcium oxide) and thermal and electrical utilities in a typical inorganic chemical process . Because commercial MCI is produced together with MIT via similar sulphur–nitrogen ring forming chemistry, the same upstream burdens apply: fossil derived feedstocks, chlorination steps, and energy intensive oxidation/cyclisation. These collectively generate GHG emissions. Broader analyses of active ingredient (API) manufacturing indicate that such chemical intensive processes contribute meaningfully to industrial emissions and require substantial decarbonisation efforts to reduce their footprint.
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C at pH 7 (mg l⁻¹)
750000
E4 E = Manufacturers safety data sheets 4 = Verified data
High
Solubility - In organic solvents at 20 °C (mg l⁻¹)
44000
E3 E = Manufacturers safety data sheets 3 = Unverified data of known source
Methanol
-
43100
E3 E = Manufacturers safety data sheets 3 = Unverified data of known source
Ethyl acetate
-
40700
E3 E = Manufacturers safety data sheets 3 = Unverified data of known source
Toluene
-
2800
E3 E = Manufacturers safety data sheets 3 = Unverified data of known source
n-Hexane
-
Melting point (°C)
52
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
-
Boiling point (°C)
200
E3 E = Manufacturers safety data sheets 3 = Unverified data of known source
-
Degradation point (°C)
-
-
-
Flashpoint (°C)
-
-
-
Octanol-water partition coefficient at pH 7, 20 °C
P
3.39 X 1000
Calculated
-
Log P
0.53
E3 E = Manufacturers safety data sheets 3 = Unverified data of known source
Low
Fat solubility of residues
Solubility
-
-
-
Data type
-
-
-
Density (g ml⁻¹)
1.02
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
-
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
-
-
-
Surface tension (mN m⁻¹)
-
-
-
Degradation
Property
Value
Source; quality score; and other information
Interpretation
General biodegradability
Biodegradable at modest concentrations. At high concentrations CMIT can inhibit the microorganisms that cause its degradation.
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 (lab at 20 °C)
-
-
-
DT₅₀ (field)
-
-
-
DT₉₀ (lab at 20 °C)
-
-
-
DT₉₀ (field)
-
-
-
DT₅₀ modelling endpoint
-
-
-
Note
Limited study
Soil mineralisation
Aerobic (at 20 °C)
-
-
-
Anaerobic (at 20 °C)
-
-
Dissipation rate RL₅₀ (days) on plant matrix
Value
-
-
-
Note
-
Dissipation rate RL₅₀ (days) on and in plant matrix
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)
-
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Moderately mobile
Koc (mL g⁻¹)
87
Notes and range
Koc range 30-144 mL g⁻¹
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
-1.32
Calculated
Low leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
1.03 X 10-04
Calculated
-
Note
-
Potential for particle bound transport index
Low
Calculated
-
Potential for loss via drain flow
Moderately mobile
Calculated
-
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk
-
-
-
Bio-concentration factor
BCF (l kg⁻¹)
114
E3 E = Manufacturers safety data sheets 3 = Unverified data of known source
Threshold for concern
CT₅₀ (days)
-
-
Known metabolites
None
ECOTOXICOLOGY
Terrestrial ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
> 481
E3 E = Manufacturers safety data sheets 3 = Unverified data of known source
Rat
Moderate
Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)
-
-
-
Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)
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)
3.9
F2 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 ) 2 = Unverified data of unknown source
Apis mellifera MIT/CMIT mixture
Moderate
-
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)
-
-
-
Beneficial insects (Butterflies)
Contact
-
-
-
Notes
-
Oral
-
-
-
Notes
-
Aquatic ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)
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
Tzilivakis, J., Lewis, K.A., Green, A. and Warner, D.J. (2026) A decade of growth and impact of the Pesticide Properties Database (PPDB). Human and Ecological Risk Assessment: An International Journal, 32(6), 1104-1129. DOI: 10.1080/10807039.2026.2702066
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
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Environmental fate
Warning:
