Controlling Biological Growth (Slimes) In Processing Tank Solutions 

PROXEL GXL: PROXEL GXL is the tradename of the solution of 1,2-benzisothiazolin-3-one (BIT), Sodium hydroxide, and dipropylene glycol. It is made by:

Arch Treatment Products -- Biocides
1955 Lake Park Drive, Suite 100
Smyma, GA 30080
Phone: (800) 523-7391

The active ingredient in PROXEL GXL is BIT and has potential to induce human skin sensitization (rash) but it is dependent on the person like poison ivy. It is corrosive as the pH is approximately 12 in the concentrate received from the manufacturer. It is a brown liquid with a slight odor.

It is used at a concentration of 0.07 ml/liter in ECN and ECP final rinse tank and replenisher formulations.

It is more stable than Spectrus NX106 in alkaline (greater than pH 9) systems. It is more stable over a wider range of temperatures. PROXEL GXL is recommended in the prebath and final rinse of ECN/ECP processes. Spectrus NX106 is not recommended for use in the prebath solution. Labs should dilute PROXEL GXL 1 :9 with water and then deliver 0.7 to 4.2 ml per liter of this 10% dilution solution of PROXEL GXL. There were no adverse sensi or image stability effects at these concentrations. PROXEL is an effective biocide in preventing the growth of most forms of organisms involved in bio slime formation.

Spectrus NX106: Spectrus NX106 is a corrosive liquid. It is amber to pale green in color with a mild aromatic odor.

Chemically, it is a mixture of 1.15% 5-chloro-2-methyl-4-isothiazolin-3-o, 0.35% 2-methyl-4-isothiazolin-3-one, magnesium chloride(less tha 2%), magnesium nitrate(less than 3%), and water to make 100%.

The Spectrus NX106 tank concentration in the final rinse is 0.7 ml/liter or ten times higher than PROXEL GXL.

Spectrus NX106 is not suitable for use above 90 degrees F. It is not as stable as PROXEL at pH greater than 9.

Spectrus NX106 is available from:

BetzDearborn, Division of Hercules Incorporated
4636 Somerton Road
Trevose, PA 19053
Business telephone: (215) 355-3300

NOTE: Either Proxel GXL or Spectrus NX106 is recommended for use in the final rinse of Process ECN-2. Some cost and amount differences exist, so users should make decisions based on availability and economics.

Proxel GXL is recommended in Process ECP-2D over Spectrus NX106, as Spectrus NX106 sometimes causes fog.