Technical Data Sheet

– Trigonox V388 is a general purpose methyl ethyl ketone peroxide (MEKP) for the curing of unsaturated polyester resins in the presence of a cobalt accelerator at room and elevated temperatures.

CAS number

– 1338-23-4


– 215-661-2



Clear colorless liquid

Total active oxygen

9.8-10.0 %


Density, 20 °C

1.120 g/cm³


37 (Closed Cup) / ≥ 63 (Open Cup) °C


Trigonox V388 is general purpose methyl ethyl ketone peroxide (MEKP) for the curing of unsaturated polyester resins in the presence of a cobalt accelerator at room and elevated temperatures.The curing system Trigonox V388/cobalt accelerator is developed for general purpose GRP- and non GRP-applications such as the curing of laminating resins and castings. Practical experience throughout many years has proven that for marine applications a special MEKP with low water content and without polar compounds is demanded in order to prevent from osmosis and other problems. Trigonox V388 is the MEKP advised for this application.For room temperature application it is necessary to use Trigonox V388 together with a cobalt accelerator (e.g. Accelerator NL-49P).

Thermal stability

Organic peroxides are thermally unstable substances, which may undergo self-accelerating decomposition. The lowest temperature at which self-accelerating decomposition of a substance in the original packaging may occur is the Self Accelerating Decomposition Temperature (SADT). The SADT is determined on the basis of the Heat Accumulation Storage Test.




The Heat Accumulation Storage Test is a recognized test method for the determination of the SADT of organic peroxides (see Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria – United Nations, New York and Geneva).


Due to the relatively unstable nature of organic peroxides a loss of quality can be detected over a period of time. To minimize the loss of quality, Nouryon recommends a maximum storage temperature (Ts max.) for each organic peroxide product.

Ts Max.


Ts Min.



When stored under the recommended storage conditions, Trigonox V388 will remain within the Nouryon specifications for a period of at least 6 months after delivery.

Packaging and transport

The standard packaging is a 30 l HDPE can (Nourytainer) for 20 kg peroxide solution.Both packaging and transport meet the international regulations. For the availability of other packed quantities contact your Nouryon representative.Trigonox V388 is classified as Organic peroxide type D; liquid; Division 5.2; UN 3105; PG II.

Safety and handling

Keep containers tightly closed. Store and handle Trigonox V388 in a dry well-ventilated place away from sources of heat or ignition and direct sunlight. Never weigh out in the storage room.Avoid contact with reducing agents (e.g. amines), acids, alkalis and heavy metal compounds (e.g. accelerators, driers and metal soaps). Please refer to the Safety Data Sheet (SDS) for further information on the safe storage, use and handling of Trigonox V388. This information should be thoroughly reviewed prior to acceptance of this product. The SDS is available at

Major decomposition products

Carbon dioxide, Water, Acetic acid, Formic acid, Propanoic acid, Methyl ethyl ketone

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