Dazomet
[CAS# 533-74-4]

Identification

• Classification: Chemical pesticide >> Fungicide >> Other fungicides
• Name: Dazomet
• Synonyms: 3,5-Dimethyltetrahydro-1,3,5-thiadiazine-2-thione; 2-Thio-3,5-dimethyl-tetrahydro-1,3,5-thiadiazine; 3,5-Dimethyl-1,2,3,5-tetrahydro-1,3,5-thiadiazinethione-2
• Molecular Formula: C₅H₁₀N₂S₂
• Molecular Weight: 162.27
• CAS Registry Number: 533-74-4
• EC Number: 208-576-7
• SMILES: CN1CN(C(=S)SC1)C

Properties

• Water solubility: <0.1 g/100 mL at 18 °C
• Density: 1.3±0.1 g/cm³, Calc.^*, 1.3 g/mL (Expl.)
• Melting point: 104-105 °C (Expl.)
• Index of Refraction: 1.656, Calc.^*
• Boiling Point: 222.3±50.0 °C (760 mmHg), Calc.^*
• Flash Point: 88.2±30.1 °C, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07;GHS09 Warning
• Risk Statements: H302-H315-H319-H400-H410
• Safety Statements: P264-P264+P265-P270-P273-P280-P301+P317-P302+P352-P305+P351+P338-P321-P330-P332+P317-P337+P317-P362+P364-P391-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Acute toxicity	Acute Tox.	4	H302
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Skin irritation	Skin Irrit.	2	H315
Skin sensitization	Skin Sens.	1	H317
Specific target organ toxicity - single exposure	STOT SE	3	H335
Specific target organ toxicity - single exposure	STOT SE	2	H371
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Reproductive toxicity	Repr.	1A	H360
Specific target organ toxicity - repeated exposure	STOT RE	1	H372
Specific target organ toxicity - single exposure	STOT SE	3	H336

Discovery and Applications

Dazomet, also known by its chemical name 1,3-dimethyl-2-imidazolidinylidene, is a chemical compound primarily used as a soil fumigant and pesticide. It belongs to a class of chemicals known as soil sterilants, which are used to control a wide range of pests, including nematodes, fungi, and weeds. Dazomet is highly effective in agricultural practices, particularly in the control of soil-borne pathogens that can harm crops. Its discovery and subsequent development have had a significant impact on pest control strategies, especially in the agriculture and horticulture sectors.

The discovery of dazomet dates back to the 1960s when researchers were exploring the potential of imidazolidine derivatives for agricultural applications. The compound was found to be effective in controlling various pests in soil, making it a valuable tool for crop protection. Dazomet works by releasing methyl isothiocyanate (MITC) upon hydrolysis. MITC is a toxic compound that can kill a wide variety of soil-borne pathogens and pests, thus providing an effective means of preventing crop damage.

Dazomet is applied to soil either before planting or as part of soil treatment programs. It is typically used in the form of granules, which are mixed into the soil or applied as a broadcast treatment. Once applied, dazomet decomposes in the soil to release MITC, which then penetrates the soil and targets various pests. This mechanism of action makes dazomet highly effective in preventing diseases caused by nematodes, fungi, and other harmful microorganisms.

One of the primary applications of dazomet is in the fumigation of soil used for growing vegetables, fruits, and ornamental plants. It has been used extensively in both conventional and organic farming to protect crops from soil-borne diseases. For example, dazomet is used to control nematodes, which can significantly reduce crop yields by damaging plant roots. In addition, it is effective against soil fungi such as Fusarium and Verticillium, which can cause root rot and wilt in various crops.

In addition to its agricultural uses, dazomet has also found applications in horticulture, where it is used to treat greenhouse soils and plant nurseries. By eliminating harmful pests and pathogens from the soil, dazomet helps ensure healthy plant growth, ultimately leading to higher-quality products and improved crop productivity. It is particularly useful in high-value crops where maintaining soil health is essential for maximizing yield and quality.

However, the use of dazomet has raised concerns regarding its environmental impact and potential health risks. Like many other chemical pesticides, dazomet can have toxic effects on non-target organisms if not applied correctly. The release of MITC into the environment can pose risks to human health and aquatic life, prompting regulatory bodies in several countries to establish strict guidelines for its use. Despite these concerns, dazomet remains an important tool in integrated pest management (IPM) systems due to its efficacy in pest control.

In conclusion, dazomet is a highly effective soil fumigant with a broad range of applications in agriculture and horticulture. Its discovery in the 1960s revolutionized pest control by providing an efficient means of managing soil-borne diseases and pests. While it continues to be used widely in farming and gardening, its environmental and health impacts highlight the need for careful and regulated application. As research continues, more sustainable alternatives and improved application methods may further enhance the role of dazomet in modern agriculture.

References

2023. The effect of surfactant on fungitoxicity of dazomet-micelle nanodelivery system against Ganoderma boninense. Chemical Papers, 77(7).
DOI: 10.1007/s11696-023-02760-0

2023. Soil nitrification process played a key role in alleviating continuous cropping limitation induced by fumigation. Plant and Soil.
DOI: 10.1007/s11104-023-05911-0