The use of mineral spirits, petroleum distillates, stoddard, and other solvents in parts cleaners is common practice. The practice usually consists of dipping or soaking metal parts in a cold solvent for the purpose of cleaning and degreasing.

Many people and companies are unaware that environmental regulations need to be complied with when using cold solvent parts cleaner to ensure that harmful vapors are not being released. You may have to obtain an air permit or adhere to operating rules.

Air Permits – open top cold solvent parts cleaners may require an air permit. An open top cold solvent parts cleaner is defined as a “sink-on-a-drum” or “immersion” style, where parts are put in or taken out from the top (even if the unit has a tightly-fitting lid). You will need an air permit if the top opening measures more than 6 square feet or the solvent capacity is greater than 100 gallons.

Operating Rules – if a cold solvent parts cleaner has the storage capacity of two (2) gallons or more of solvent, then the following operating rules must be followed:

  • Solvent used must have a vapor pressure of <1 mm Hg at 20°C / 68°F
  • The parts cleaner must be equipped with a tightly-fitting lid
  • A copy of the NJDEP operating rules must be posted by the parts cleaner
  • Records of solvent purchases must be maintained for 2 years

Immersion parts cleaners:

  • The cover must be kept closed, except when adding or removing parts or solvent
  • The unit must have a freeboard ratio of 0.75 or more – freeboard ratio = height measured from the top of the solvent surface up to the top of the unit, divided by the width of the narrowest part (dimension) of the storage container
  • The storage container must have a liquid fill-line and a high-level liquid mark

Sink-on-a-drum parts cleaner:

  • The cover must be kept closed when not in use, except when parts are draining, in which case, the solvent must be drained directly into a sealed container, and the drain must be kept clear with no liquid solvent present in the sink

Note: heated solvent parts cleaners and vapor degreasers are subject to different regulations