Cresol (Mixed Isomers) (1319-77-3)
Cresol (Mixed Isomers) is a aromatic hydrocarbon with CAS Registry Number 1319-77-3. 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 5 ppm. The principal target organs are the Skin; eyes; CNS, and workplace air is sampled and analyzed by NIOSH 2546.
Exposure Limits at a Glance
| Limit | Value | Basis |
|---|---|---|
| OSHA PEL (8-hr TWA) | 5 ppm | 29 CFR 1910.1000 |
| NIOSH REL | See note below | NIOSH Pocket Guide |
| Hazard Class | Aromatic Hydrocarbon | Aromatic |
| Target Organs | Skin; eyes; CNS | NIOSH / OSHA |
| Sampling Method | NIOSH 2546 | NIOSH Manual of Analytical Methods |
NIOSH REL note: NIOSH RELs are typically far more protective (e.g. benzene 1 ppm PEL vs 0.1 ppm REL). 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 Cresol (Mixed Isomers) is assessed against the Skin; eyes; CNS — the organ systems most consistently affected in occupational studies. Employers must ensure no employee’s 8-hour TWA exceeds the 5 ppm PEL, and must use engineering controls, work practices, and — where required — respiratory protection to keep exposures at or below that level.
- Hazard class: Aromatic Hydrocarbon. Aromatic-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 2546 for laboratory analysis.
- Medical surveillance: consult the OSHA substance-specific standards and the NIOSH Pocket Guide when the target organs are the Skin; eyes; CNS.
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 Aromatic-class agents regardless of the 8-hour average.
- Calibrate personal sampling pumps before and after each shift and record flow rates; method NIOSH 2546 specifies media, flow, and analysis.
- Compare analytical results to the OSHA PEL of 5 ppm 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 Cresol (Mixed Isomers)?
The OSHA Permissible Exposure Limit (8-hour TWA) for Cresol (Mixed Isomers) is 5 ppm.
What is the CAS number for Cresol (Mixed Isomers)?
The CAS Registry Number for Cresol (Mixed Isomers) is 1319-77-3.
What are the target organs for Cresol (Mixed Isomers)?
The primary target organs are the Skin; eyes; CNS.
How do you measure Cresol (Mixed Isomers) in workplace air?
Use NIOSH analytical method NIOSH 2546 for air sampling and laboratory analysis.
What hazard class is Cresol (Mixed Isomers)?
It is classified here as a Aromatic Hydrocarbon (Aromatic).