Which drugs are classified as hazardous drugs? A Guide to NIOSH and Safe Handling

October 11, 2025 •

2 min read

According to the CDC, millions of healthcare workers could be exposed to hazardous drugs, which pose significant health risks if not handled correctly. This guide explains the criteria for determining which drugs are classified as hazardous drugs, detailing the official classifications from the National Institute for Occupational Safety and Health (NIOSH).

Quick Summary

Hazardous drugs are identified by NIOSH for causing serious health effects, including cancer, developmental issues, and organ toxicity. Handling requires strict safety protocols.

Key Points

NIOSH Criteria: A drug is hazardous if it is carcinogenic, genotoxic, teratogenic, reprotoxic, causes organ toxicity at low doses, or mimics other hazardous drugs.
Three Groups: NIOSH classifies hazardous drugs into three groups: antineoplastics (chemotherapy), non-antineoplastics, and drugs posing only reproductive risks.
Antineoplastic Examples: Many common chemotherapy agents like Cyclophosphamide, Fluorouracil, and Doxorubicin are hazardous.
Non-Antineoplastic Examples: This group includes a variety of potent drugs such as the immunosuppressant Mycophenolate and the anticoagulant Warfarin.
Reproductive Risk Examples: Some medications, like the anxiolytic Clonazepam and the labor-inducing Oxytocin, are hazardous due to specific reproductive risks.
Safe Handling is Critical: Standards like USP <800> require engineering controls (BSCs), specific PPE, and proper waste disposal to minimize exposure.
Risk Assessment: An Assessment of Risk (AoR) can sometimes be performed for less risky dosage forms of non-antineoplastic drugs to determine alternative handling procedures.

What Defines a Hazardous Drug?

The National Institute for Occupational Safety and Health (NIOSH) classifies a drug as hazardous if it exhibits one or more of six characteristics in humans or animals: carcinogenicity, genotoxicity, teratogenicity or developmental toxicity, reproductive toxicity, organ toxicity at low doses, or if it mimics existing hazardous drugs. These properties, while making drugs effective for patients, pose risks to healthy individuals through occupational exposure. Protecting healthcare workers from exposure during handling is crucial.

The NIOSH Hazardous Drug Classification System

NIOSH categorizes hazardous drugs into three groups to guide appropriate handling procedures.

Group 1: Antineoplastic Drugs

These are primarily cancer treatments that interfere with cell growth, making them highly hazardous upon exposure.

Examples of Group 1 Hazardous Drugs:

Alkylating Agents: Cyclophosphamide, Carboplatin, Cisplatin.
Antimetabolites: Fluorouracil (5-FU), Gemcitabine.
Anthracyclines: Doxorubicin, Irinotecan.
Taxanes: Paclitaxel, Docetaxel.
Miscellaneous: Bortezomib, Arsenic trioxide.

Group 2: Non-antineoplastic Drugs

This group includes drugs meeting hazardous criteria but not used for cancer. Examples are immunosuppressants, hormones, and antivirals.

Examples of Group 2 Hazardous Drugs:

Immunosuppressants: Mycophenolate mofetil, Azathioprine, Sirolimus.
Hormones: Estrogens, Progesterone, Spironolactone.
Antivirals: Ganciclovir, Ribavirin.
Others: Warfarin, Finasteride.

Group 3: Reproductive Risk Only

These drugs specifically pose a reproductive risk.

Examples of Group 3 Hazardous Drugs:

Alitretinoin.
Clonazepam.
Colchicine.
Misoprostol.
Oxytocin.
Warfarin (also in Group 2).

Comparison of Hazardous Drug Categories


Feature	Group 1: Antineoplastic Drugs	Group 2: Non-antineoplastic Drugs	Group 3: Reproductive Risk Only
Primary Risk	Multiple risks, including carcinogenicity and reproductive toxicity	Multiple risks, not cancer-specific	Primarily reproductive risks
Typical Use	Cancer treatment	Various conditions	Conditions posing specific reproductive health risks
Handling Controls	Most stringent engineering controls and PPE under USP <800>	Containment and PPE; Assessment of Risk possible for certain forms	Specific handling and counseling, especially for reproductive-age staff
Examples	Doxorubicin, Paclitaxel	Spironolactone, Ganciclovir	Clonazepam, Warfarin

Safe Handling and Risk Assessment

Strict safety protocols are vital when handling hazardous drugs. Standards for minimizing exposure are outlined, such as in USP General Chapter <800>.

Key Safety Practices:

Engineering Controls: Use of Biological Safety Cabinets (BSCs) and Closed System Transfer Devices (CSTDs).
Personal Protective Equipment (PPE): Required use of chemo-rated gloves, gowns, and respiratory protection.
Proper Waste Management: Segregation and correct disposal of hazardous drug waste.
Training: Personnel must be trained on safe handling.

For some Group 2 and 3 drugs, an Assessment of Risk (AoR) can determine if alternative handling strategies are acceptable based on factors like dosage form and manipulation required.

Conclusion: The Importance of Awareness and Adherence

Recognizing hazardous drugs using the NIOSH list is crucial for a safe healthcare environment. Following guidelines like USP <800> is essential for protecting worker health and preventing long-term issues such as infertility and cancer. Implementing robust protocols allows for the safe use of these drugs while safeguarding personnel. Healthcare professionals should regularly check official NIOSH lists for updates.

For the latest NIOSH updates, consult {Link: CDC website https://www.cdc.gov/niosh/topics/hazdrug/default.html}.

Frequently Asked Questions

A hazardous drug is a medication identified by NIOSH that can cause serious health effects, such as cancer, organ toxicity, or reproductive harm, in workers who handle it.

The National Institute for Occupational Safety and Health (NIOSH) is the primary organization that evaluates and publishes a list of hazardous drugs in healthcare settings based on specific toxicity criteria.

Yes, nearly all antineoplastic (chemotherapy) drugs are considered hazardous due to their potent nature and ability to interfere with cell growth.

No, hazardous drugs can cause a range of serious health effects beyond cancer, including reproductive issues, developmental toxicity, genotoxicity, and organ damage at low doses.

USP General Chapter <800> outlines official standards for the safe handling of hazardous drugs.

Yes. NIOSH's Group 2 includes non-antineoplastic drugs like some hormones, antivirals, and immunosuppressants that still meet the criteria for being classified as hazardous.

Drugs that pose only a reproductive risk include Alitretinoin, Clonazepam, and Oxytocin. These drugs can have teratogenic or other adverse effects on fetal development or fertility.