What Steps Should Be Taken to Work Safely in Enclosed Areas?
Follow proper lock-out / tag-out procedures and never work alone.
If a fellow worker becomes overwhelmed by solvent vapors, call for assistance, and wait for that assistance to arrive. Use the appropriate secondary air packs, and then approach the distressed worker, make sure a fellow worker is staying behind (outside of the affected area) ready to call for additional help if necessary.
What Kind of Safety Gear Should I Use With the MicroCare Cleaners?
Proper PPE should always be used in any industrial operation. Safety glasses and chemical resistant gloves are a good start. Splash aprons, respirators with halogenated cartridges, and secondary breathing apparatus may be necessary during maintenance, depending on the level of possible chemical exposure. MicroCare personnel encourage customers to be liberal in their use of PPE when working with any chemical.
What Is the TLV for nPB? Why Is It Now Considered Toxic?
A “Threshold Limit Value” (TLV, also called AEL or PEL) is the most common toxicity measurement defined by the American Conference of Governmental Industrial Hygienists (ACGIH). A high number means a safer fluid, a low number is more toxic. A TLV measures the parts per million of chemical exposure to which a worker may be exposed over an 8-hour work day for a 30-year working career without health hazards.
Previously, ACGIH had assigned a TLV to n-propyl bromide (nPB) of 10 parts per million. However, recently the ACGIH has revised their rating to 0.1 parts per million. It is expected this TLV will become the industry standard in the months and years ahead. In practical terms, this means the fluid cannot be used in any traditional vapor degreaser without exceeding the safety limits. All the replacement fluids from MicroCare have much, much higher TLV values for improved worker safety.
What Are the Standard Vapor Degreasing Processes?
Both nPB and the replacement fluids from MicroCare all are designed to be used in a vapor degreaser. There are six steps to this type of cleaning: (1) The parts are placed into a basket. (2) The basket is moved into the boil sump for an initial cleaning of 2 – 10 minutes. (3) The parts are raised briefly into the vapor zone to allow excess solvent to drip back into the boil sump. (4) The parts are moved to the rinse sump for 2-10 minutes. (5) The parts receive a final rinse by lifting them into the vapor zone for 30 seconds. (6) After that, the parts are dried by slowly moved up and out of the degreaser. They come out clean, dry and near room temperature. Generally speaking, total cycle times normally range from six to twenty minutes.
How Do I Ship the MicroCare Cleaners? Dispose of Them?
MicroCare cleaners are nonflammable and so are shipped as “DOT non-hazardous.” In terms of disposal, recycle the spent solvent whenever practical. Handle the empty containers and spent solvent according to Federal, State and local regulations. Contact MicroCare for more details.
For These New Fluids, Does the Handling Change? Which Drum Pumps Do You Recommend? Where Can I Buy Them?
The handling and storage does not change. Keep your cleaning fluids in a cool, dry location out of direct sunlight. Use stainless steel drum pumps with Teflon seals. They are available from numerous catalog supply companies.
Do the New Cleaners “Turn Acid” Like the Old-Style Solvents Did?
The replacement solvents for nPB from MicroCare are thermally and hydrolytically stable. The MicroCare fluids will not turn acidic unless (1) exposed to a strong base or acid, or (2) if exposed to extreme heat, such as when the heater elements become exposed and “burn” the solvent. These fluids will not require the stabilizers or scavengers that were common with nPB and TCE.
Do the MicroCare Replacement Cleaners Have Materials Compatibility Problems?
In general, no. The nPB replacements from MicroCare will have the same or better materials compatibility as the nPB they are replacing.
Do the MicroCare Replacement Cleaners Have High Kb Values Like nPB?
Yes, some of them do. MicroCare offers a large family of cleaning fluids with a variety of Kb values, which enables engineers to fine-tune their cleaning process.
Kb value refers to a standardized ASTM test (Method D-1133) that measures the relative strength of a solvent. Kb values range from 10 (very mild) to 200 or even higher (very strong cleaning). Solvents with lower Kb values will dissolve greases but may not handle ionics and fluxes. Solvents with higher Kb values may be speedy and effective flux removers but may attack plastic components or remove inks. The Kb values for the MicroCare products listed here range from 20 to 96.
However, there’s a caveat to insert here: while often used, Kb values do not tell the whole cleaning story. Kb values are subject to wide variations due to nuances in the test procedures. It also can produce some exotic results especially with alcohol formulas or at higher ranges. Cleaning results also can be affected by other factors such as surface tension, density and viscosity. In short, yes, we use the term and we know the test method, but it should only be considered an approximation that needs to be validated with real-world cleaning tests.
Do I Have to Change My Degreaser Operations, such as the Speed of the Degreaser Hoist?
Everybody likes to claim their new solvents are “drop-in” replacements for whatever you were using before. While MicroCare empathizes with the desire of a sales rep to keep things simple, the term “drop in” is a misnomer. If a vapor degreaser is not properly cleaned between solvents then residues from the old solvent can cause problems.
You see, nPB and TCE require chemical stabilizers to protect the solvent from small quantities of acids or water that cause the solvent to “turn acid.” Once acidic, the solvent will attack the vapor degreaser and the parts being cleaned. You must be sure there is no residual solvent left in the degreaser before adding the new fluid.
Therefore, when converting a vapor degreaser to a new fluid it is best to neutralize and re-passivate the machine. In this manner, you are ensured that no legacy solvents — that is, small traces of nPB or TCE— are left in the machine. This is because the new MicroCare fluids do not contain any stabilizers, so any residual nPB or TCE trapped in the machine quickly will turn acidic. This, in turn, will compromise your degreaser, your parts and your solvent even though only a tiny portion of the old cleaner is involved.
There are a few other changes that may be required. The most common change is to lower the temperatures in the degreaser; this is because nPB boils at 70˚C while most of the replacement cleaners are around 41˚C. Depending upon the replacement fluid selected, the cleaning cycles may be slightly extended. But the other operating parameters, such as hoist speeds, should remain unchanged. The normal recommended hoist speed should move no faster than 11 feet per minute. For some intricate parts or heavily laden baskets, slower speeds can help reduce fugitive emission loses.
Can the MicroCare Cleaners Be Recycled or Reclaimed?
Yes, absolutely. That’s the beauty and the benefit of vapor degreasing. Recycling is an inherent characteristic of the vapor degreasing process. The solvents simply never wear out. MicroCare degreasing solvents can be recycled thru simple distillation in the degreaser itself or in a supplement distillation system if extra throughput is required.
Are the MicroCare Vapor Degreasing Fluids Flammable?
No. All of the solvent formulations that MicroCare provides for vapor degreasing are non-flammable, and will not become flammable under normal use. MicroCare takes safety very seriously, and will not provide solvents for applications that are not deemed safe.
Are the MicroCare Replacement Cleaners Azeotropes?
Yes, the recommended nPB replacements from MicroCare are azeotropes or near-azeotropes which will perform very well in a vapor degreaser. An azeotrope, simply put, is a mixture of two or more chemicals which behave as if they were one chemical. This new chemical will repeatedly boil to a vapor then condense back to its original proportions without separating. A true azeotrope will last a long time in a vapor degreaser. Fluids that are not azeotropes will quickly separate into their individual components and leave the system at different rates, causing either a drop in cleaning performance, a rise in flammability, or both.
Are the MicroCare Cleaning Fluids S.N.A.P. Approved and Accepted?
All of the various fluids in the MicroCare product line have received EPA SNAP approval for use in vapor degreasing applications.
Learn More About MicroCare
MicroCare is the industry leader in critical cleaning. Whether it is electronics, precision metal parts, aeronautics or surgical instruments, companies rely on MicroCare products and expertise to deliver perfectly clean parts, every time, at the lowest possible cost.