Important Methyl Ethyl Ketone Peroxide (MEKP) Safety Information
83A2012J
Important Methyl Ethyl Ketone Peroxide (MEKP) Safety Information
MEKP is among the more hazardous materials found in commercial channels. Pr oper handling of the “unstable
(reactive)” chemicals presents a serious challenge to the plastics industry. The highly reactive property which makes
MEKP valuable to the plastics industry in producing the curing reaction of p olyester resins and gel-coats also pro-
duces the hazards which require great care and caution in its storag e, transportation, handling, processing and dis-
posal.
Workers must be thoroughly informed of the hazards that may result from improper handling of MEKP, especially in
regard to contamination and heat. They must be thoroughly instructed regar ding the proper storage, use and dis-
posal of MEKP and other hazardous materials used in the laminating operation.
MEKP is flammable and potentially explosive, as well as potentially d amaging to the eyes and skin.
Read material manufacturer’s warnings and material MSDS to know specific hazar ds and precautions related
to MEKP.
Contaminated MEKP can become explosive. Prevent contamination of ME KP with other materials, including
but not limited to polyester overspray, polymerization accelerators and p romoters, and non-stainless metals.
Even small amounts of contaminates can make MEKP explosive. Thi s reaction may start slowly, and gradually
build-up heat, which can accelerate until fire or an explosion result. Th is process can take from seconds to
days.
Heat applied to MEKP, or heat build-up from contamination reactions c an cause it to reach what is called its
Self-Accelerating Decomposition Temperature (SADT), which can caus e fire or explosion. Spills should be
promptly removed, so no residues remain. Spillage can heat up to the point of self-ignition. Dispose in accor-
dance with manufacture’s recommendation.
Store MEKP in a cool, dry and well-ventilated area in the original container s away from direct sunlight and
away from other chemicals. It is strongly recommended that the storage tem perature remain below 86° F
(30° C). Heat will increase the potential for explosive decomposition. Refer to NFPA 432. Keep MEKP away
from heat, sparks and open flames.
Current catalysts are premixed and do not require any diluents. Graco strong ly recommends that diluents not
be used. Diluents add to the possibility of contaminates entering the catal yst system. Never dilute MEKP with
acetone or any solvent since this can produce an extremely shock-sensitive c ompound which can explode.
Use only original equipment or equivalent parts from Graco in the catal yst system (i.e.: hoses, fittings, etc.)
because a hazardous chemical reaction may result between substituted pa rts and MEKP.
To prevent contact with MEKP, appropriate personal protective equipmen t, including chemically impermeable
gloves, boots, aprons and goggles are required for everyone in the work area.