Hex Chromium           

Cr(VI), chromates, dichromates,  chromic acid, chromium trioxide

                                                

 Hexavalent chromium is found in many industrial environments.  These include chrome plating operations (chromic acid), painting (chromates and dichromates), welding on high chrome steels (CrO3), as well as others. The current OSHA PEL TWA for all forms of Cr(VI) is 5.0 µg/m3 as Cr(VI) with an action level of  2.5 µg/m3.  The previous PEL was a Ceiling level of 52 µg/m3 (0.1 mg/m3 as CrO3).  Please visit http://www.osha.gov/SLTC/hexavalentchromium/index.html  for more information. 

 

Hexavalent chromium requires special handling, sampling, media, and analysis procedures depending on the type of sample.

 

SAMPLING PLATING OPERATIONS

Because Cr(VI) is not stable under acidic conditions OSHA recommends using a 37 mm sodium hydroxide (NaOH) treated quartz fiber filter (WOHL media number 159 - clear band - labeled Cr6 acid).  Please only use these for plating or sampling in acidic environments.  The filters are only good for one month from the time made.  These filters will be made only on an as needed basis.  Please allow for a 2-3 day preparation time and shipping time when you place your order. 

 

SAMPLING PAINTING OPERATIONS

Samples from spray painting operations should be collected 37 mm 5 micron, unweighed, PVC filters (WOHL media #86 - clear band - labeled Na/K/Cr6).  It is important that you let the laboratory know if samples are taken from spray painting operations.  A 2nd more vigorous digestion and analysis procedure is needed to recover all the Cr(VI) from the paint (extra charges may apply).  If we don't know that these samples are from paint, results will likely be suspect.

 

SAMPLING WELDING OPERATIONS              stainless

Samples taken from welding and all other operations are collected on 37 mm 5 micron, unweighed PVC filters (WOHL media #86 - clear banded - labeled Na/K/Cr6).  These are also available in the 25 mm 5 micron PVC (WOHL media #161 - labeled  Cr6 weld).    It is advisable to send the samples to lab as soon as possible (preferable within 24 hours).  Welding samples need to be analyzed within 8 days.