PEL-RON 822 is a unique copper complex that works to lower the required amount of biocidal agents required to stabilize diluted metal working fluids in use. Thus it helps to reduce the usual dose of biocide required. For example, the level of isothiazolinone biocide required can be reduced by up to 20% when formulated with PEL-RON 822. It will often eliminate and prevent the recurrence of most coolant borne odors such as that of hydrogen sulfide from sulfur reducing bacteria.