DCOIT Is a broad spectrum fungicide. It can be widely used in paint, coating, polyethyl ene, polyamine ester and other plastic industry, leather, paint, coating, sewage,  paper making, wood, adhesive, ink and other fields. It can replace compounds suc h as organic arsenic, which is extremely toxic. 

Name: DCOIT  

CAS NO.:64359-81-5  

Molecular formula :C11H17NOSCl2  

Molecular weight:282  

Basic overview chemical name: DCOIT (4,5-dichloro-n-octyl-4-isothiazolin-3-one) isothiazolinone derivative,quality criteria.  

Appearance: White to light yellow powder  

Active ingredient ≥98.00%  

Scope of application  Antibacterial agent, preservative, can effectively kill cyanobacteria, basidiomyc etes, aspergillus Niger, fusarium, Curvularia, viridis etc.  

Application environment  

1. Carrier to use: diisomallow phthalate (DIDP), polyvinyl chloride (PVC)  

2. General purpose solvents: Glycole or Alcohol derivatives, Xylene  

3. Stabilize in ocean paint;  

4. The latest slow-release technology, broad-spectrum efficient for killing bacte ria, fungi, seaweed and other Marine life;  

5. Provide lasting protection that meets or exceeds the effects of TBTO;  

6. Heavy metal-free. When released into the environment, DCOIT quickly seeps into  sediments and breaks down, so it does not accumulate in Marine life;  

1. Stable under strong UV and acid rain conditions; Willingham et al. found that: The antifouling coating containing Sea-Nine211(30% DCOIT) had a strong inhibitory effect on the mucous membrane formation of Marine bacteria, and the minimum inhibitory concentration MIC for Pseudomonasatlantica a nd Pseudomonasnautica were both 0.1mg/L. Xie Junbin et al. reported that isothiazolinone had good killing and inhibiting effects on heterotrophic bacteria, Staphy lococcus aureus, Escherichia coli, Candida albicans, Proteus, Diplococcus cala, gram-positive bacteria, negative bacteria, fungi and yeast.  

2. Algal inhibition performance Willingham et.al pointed out that Sea-Nine211 antifouling agent has strong killin g effect on algae Enteromorpha and diatom Amphoracoffeaeformis, with LD50 of 0.00 2mg/L and 0.003mg/L, respectively. Jiang Tao et al. found that isothiazolinone had a strong killing effect on Phaeocystis globosa, Marine unicellular algae and pa lmidium. 

3. Inhibition of barnacles Barnacles are one of the most widespread and abundant Marine defilers in the world; It is also the most harmful and frequent fouling organism to ship bottom; At the same time, it is the most important component of pipeline fouling organisms. U nlike other non-metabolic bactericides, Sea-Nine211 antifouling agent has a good killing effect on barnacles. Willingham et al pointed out that the LD50 of Sea-Nine antifouling agent on barnacles larvae was only 0.34mg/L.  

4. Toxicity to non-target organisms Shade et al.'s study on the related ecospecies-toxicological effects of Sea-Nine 211 found that Sea-Nine211 had a 96h semi-lethal concentration of 2.7μg/L for ra inbow trout (Salmogairdneri) in the flow test and a 96h semi-lethal concentration  of 9.7μg/L in the static test. OkamuraH et al's experimental results showed t hat the 28d semi-lethal concentration of Sea-Nine211 for salmogairdneri was 14μg /L.  

2. Migration, transformation and distribution in the environment the ideal antifouling agent needs to meet the following conditions to ensure that  the negative impact on the environment is under control, including: can degrade rapidly in the environment; Rapid distribution in the environment with little bio accumulation to non-target Marine organisms; At used concentrations, it is less t oxic to non-target species.  Because DCOI is hydrophobic, after entering the environment, it is not easy to en rich in water, but more inclined to deposit in the solid phase (such as rocks, etc.), with the following characteristics:  

1) DCOIT is easily adsorbed in solid sediments, and its adsorption coefficient (Koc) can reach 15000;  

2) The metabolites of DCOIT are also easily adsorbed in solid sediments;  

3) Because there are a variety of microorganisms on the surface of soil and solid  sediment, the DCOIT adsorbed on its surface is metabolized faster;  

4) The toxicity test based on the solid surface proved that the DCOIT decompositi on products were less toxic.

1) Metabolism in anaerobic environment: half-life is less than 1h. Its metabolites can be rapidly deposited and closely adhered to the solid sediment layer;  

2) Metabolism in aerobic environment: rapid deposition of metabolites occurs when  the half-life is less than 1h.  

4. Degradation  Hydrolysis mechanism: Under acidic or alkaline conditions, the degradation mode is catalyzed, and the degradation is slowest in the neutral environment. In natura seawater (which contains a variety of microorganisms), the hydrolysis half-life  of Sea-Nine is greatly accelerated. According to the United States Environmental  Protection Agency (EPA, 1982), the half-life of Sea-Nine is less than 24h, and it is clear that the hydrolysis (degradation) of sea-nine is greatly accelerated in seawater, which is due to the greatly accelerated effect of microbial metabolis m. Photolysis mechanism: In natural seawater, the half-life of Sea-Nine is 322h and 1913h under natural light and no light, respectively, under the condition of pH n eutral. Compared with the hydrolysis half-life, the photolysis rate of Sea-Nine is slower than that of hydrolysis rate. Relatively speaking, the photolysis mechan ism is not the main decomposition pathway in the degradation mode of Sea-Nine. 

Five, the impact on the environment development direction: isothiazolinones are an important industrial fungicide and Marine antifouling agent, in order to make such compounds get the actual promotion and application, in the future research should be paid more attention, hope to continue to make breakthroughs in the follow ing three aspects:  

1) isothiazolinone compounds in the environment after the decomposition of differ ent degradation products, need to further study the composition of the product, s tructure, toxicity, whereabouts and the role of the environment and other issues;  

2) The determination of reaction order and kinetic parameters (such as degradation rate and half-life) is the key to quantitative evaluation of degradation reaction, so reaction kinetics is still one of the main research directions;  

3) Further study of the toxicological effects of isothiazolinones on non-target organisms, such as limited bioaccumulation and minimal toxicity to fish in water, to provide a theoretical basis for screening ideal fungicides.