NIOSH, the National Institute for Occupational Safety and Health, is the federal agency responsible for researching workplace safety and health hazards and recommending ways to reduce them. Established by the Occupational Safety and Health Act of 1970, it sits within the Centers for Disease Control and Prevention (CDC) and operates with a budget of roughly $363 million. Its core job is producing the scientific evidence that shapes workplace safety standards, testing and certifying protective equipment like respirators, and investigating hazards when workers or employers ask for help.
How NIOSH Differs From OSHA
The same 1970 law created both NIOSH and OSHA, but they do very different things and live in different parts of the federal government. NIOSH is a research agency housed in the Department of Health and Human Services. OSHA is a regulatory and enforcement agency housed in the Department of Labor. In simple terms, NIOSH studies workplace hazards and figures out what’s dangerous, then OSHA uses that research to set legally enforceable standards and inspect workplaces for violations.
Respirators are a good example of how they work together. NIOSH tests and approves every respirator used in occupational settings. OSHA then requires employers to use only NIOSH-approved respirators and to maintain a respiratory protection program. One agency does the science, the other writes the rules and enforces them.
Workplace Investigations
One of NIOSH’s most direct services is the Health Hazard Evaluation (HHE) program. If you’re an employee, employer, or union official who suspects something at work is making people sick, you can request an evaluation at no cost. NIOSH will review the situation and, when warranted, send a team to the workplace to assess exposures and conditions firsthand.
After the evaluation, NIOSH provides recommendations for reducing or eliminating the hazards it identified. For on-site evaluations, findings are published online in a formal report, with company and employee names removed. These reports become part of the public record and often influence how similar workplaces across the country handle the same hazards. The legal “right of entry” authority written into the original 1970 law gives NIOSH the power to make inspections and question both employers and employees during these investigations.
Respirator and Equipment Certification
If you’ve ever seen an “N95” label on a respirator, that classification comes from NIOSH. The agency’s National Personal Protective Technology Laboratory handles everything related to respirator approval: research, standards development, user guidance, and the certification program itself.
Every respirator submitted for approval must meet performance requirements outlined in federal regulations (42 CFR Part 84). Manufacturers provide data showing their product meets or exceeds these requirements, and NIOSH tests the devices using standardized procedures. Only respirators that pass receive a NIOSH approval label. This certification system is what OSHA relies on when it requires workplaces to use approved respiratory protection.
Tracking Injuries, Illnesses, and Deaths
NIOSH runs national surveillance programs that track workplace injuries, illnesses, and fatalities across the country. These systems collect data from multiple sources, including death records, hospital data, and industry-specific databases like the Fatalities in Oil and Gas database. The agency maintains Worker Health Charts that compile this information into accessible, searchable tools.
In recent years, NIOSH has pushed to get occupation and industry data included in electronic health records. The goal is to make it possible for public health systems to spot patterns, like a cluster of a particular illness in a specific occupation, that would otherwise go unnoticed. The agency has upgraded its coding tools to classify emerging industries and occupations and has worked to incorporate these data elements into national health IT standards.
Research Priorities and the National Occupational Research Agenda
NIOSH organizes its research through the National Occupational Research Agenda (NORA), a partnership program that brings together researchers, employers, workers, and other stakeholders to identify the most pressing workplace safety and health problems. NORA operates through sector-based councils, each focused on a particular part of the economy, and sets priorities that guide where research funding and attention go.
The agency also runs a Future of Work Initiative that tackles risks created by changes in how and where people work. Its scope is broad: automation and robotics, artificial intelligence, gig and app-based work arrangements, wearable exoskeletons, autonomous vehicles, and the health effects of non-standard scheduling. The initiative also addresses workforce-level concerns like burnout prevention, productive aging, economic security, and the need for reskilling as technology displaces certain jobs.
Tools for Workers and Safety Professionals
Beyond research papers, NIOSH produces practical reference tools used daily by safety professionals, industrial hygienists, and emergency responders. The most widely known is the NIOSH Pocket Guide to Chemical Hazards, a free database covering hundreds of workplace chemicals. For each substance, the guide lists recommended exposure limits, the concentration immediately dangerous to life and health, physical properties, symptoms of exposure, target organs affected, first aid information, and recommendations for personal protective equipment and respirator selection. It’s essentially a field reference for anyone who needs to quickly assess the risk of a chemical exposure.
Training the Workforce
NIOSH funds 18 university-based Education and Research Centers across the country. These centers offer graduate and post-graduate training in core occupational safety and health fields: industrial hygiene, occupational health nursing, occupational medicine, and occupational safety. Many also cover allied disciplines like occupational health psychology, ergonomics, agricultural safety, and mining safety. Beyond degree programs, the centers provide continuing education and outreach to professionals already working in the field, helping keep the pipeline of trained safety and health experts supplied.