Chromium (VI) Compounds (18540-29-9)
Chromium (VI) Compounds is a metal fume with CAS Registry Number 18540-29-9. Under the OSHA air contaminants standard (29 CFR 1910.1000), its Permissible Exposure Limit (PEL) — the legal 8-hour time-weighted average (TWA) for general industry — is 0.005 mg/m3. The principal target organs are the Respiratory tract; skin; nasal septum, and workplace air is sampled and analyzed by NIOSH 7605.
Exposure Limits at a Glance
| Limit | Value | Basis |
|---|---|---|
| OSHA PEL (8-hr TWA) | 0.005 mg/m3 | 29 CFR 1910.1000 |
| NIOSH REL | See note below | NIOSH Pocket Guide |
| Hazard Class | Metal Fume | Metal Fume |
| Target Organs | Respiratory tract; skin; nasal septum | NIOSH / OSHA |
| Sampling Method | NIOSH 7605 | NIOSH Manual of Analytical Methods |
NIOSH REL note: NIOSH RELs target the respirable fraction and apply to the specific metal species. The REL is a non-regulatory recommendation; where a NIOSH REL exists it is typically more protective than the OSHA PEL.
How It Enters the Body & Health Effects
Exposure to Chromium (VI) Compounds is assessed against the Respiratory tract; skin; nasal septum — the organ systems most consistently affected in occupational studies. Employers must ensure no employee’s 8-hour TWA exceeds the 0.005 mg/m3 PEL, and must use engineering controls, work practices, and — where required — respiratory protection to keep exposures at or below that level.
- Hazard class: Metal Fume. Metal Fume-class agents are managed with the hierarchy of controls (elimination, substitution, engineering controls, administrative controls, then PPE).
- Monitoring: collect personal air samples in the breathing zone and submit them under NIOSH 7605 for laboratory analysis.
- Medical surveillance: consult the OSHA substance-specific standards and the NIOSH Pocket Guide when the target organs are the Respiratory tract; skin; nasal septum.
Sampling & Compliance Notes
- Determine whether the exposure is a full-period 8-hour TWA or a short-term / ceiling scenario. Ceiling and STEL excursions apply to several Metal Fume-class agents regardless of the 8-hour average.
- Calibrate personal sampling pumps before and after each shift and record flow rates; method NIOSH 7605 specifies media, flow, and analysis.
- Compare analytical results to the OSHA PEL of 0.005 mg/m3 and the NIOSH REL. Document the higher of the two for internal exposure-control targets.
- Where the PEL includes a “skin” notation, dermal absorption can contribute to the dose — glove selection and hygiene facilities are part of compliance.
Frequently Asked Questions
What is the OSHA PEL for Chromium (VI) Compounds?
The OSHA Permissible Exposure Limit (8-hour TWA) for Chromium (VI) Compounds is 0.005 mg/m3.
What is the CAS number for Chromium (VI) Compounds?
The CAS Registry Number for Chromium (VI) Compounds is 18540-29-9.
What are the target organs for Chromium (VI) Compounds?
The primary target organs are the Respiratory tract; skin; nasal septum.
How do you measure Chromium (VI) Compounds in workplace air?
Use NIOSH analytical method NIOSH 7605 for air sampling and laboratory analysis.
What hazard class is Chromium (VI) Compounds?
It is classified here as a Metal Fume (Metal Fume).