HazCom, short for Hazard Communication, is an OSHA workplace safety standard that requires employers to inform workers about the dangerous chemicals they may encounter on the job. Formally known as the Hazard Communication Standard (HCS), it covers every chemical known to be present in a workplace where employees could be exposed during normal use or in an emergency. The standard places specific duties on chemical manufacturers, importers, distributors, and employers to classify chemical hazards and pass that information down the chain until it reaches the worker actually handling the product.
What HazCom Requires
The standard has a straightforward goal: no worker should use a chemical without knowing what it can do to them and how to protect themselves. To accomplish this, it creates a system with three core elements that work together. Container labels give workers an immediate visual warning. Safety data sheets provide detailed reference information. And employee training ensures workers actually understand what they’re looking at and what to do.
Every employer who has hazardous chemicals in the workplace must pull these elements together into a written hazard communication program. That written program needs to explain how the employer handles labeling, how safety data sheets are maintained and made accessible, and how workers receive training. It must also include a list of every hazardous chemical known to be present, and it must describe how employees will be informed about hazards during non-routine tasks, like cleaning equipment that normally contains chemicals, or working near unlabeled pipes.
Who It Covers
HazCom applies to any worker who may be exposed to hazardous chemicals under normal working conditions or in a foreseeable emergency. This includes factory workers, lab technicians, custodians, construction workers, auto mechanics, and countless other roles. Office workers and bank tellers who only encounter chemicals in rare, isolated situations are specifically excluded.
The definition of “hazardous chemical” is broad. It includes any chemical classified as a physical hazard (flammable, explosive, corrosive to metal, oxidizing, reactive, or pressurized) or a health hazard (toxic, cancer-causing, damaging to organs, irritating to skin or eyes, or harmful to reproductive health). It also covers simple asphyxiants, which are gases that can displace oxygen in a room, and combustible dusts.
Labels and Pictograms
Every container of a hazardous chemical shipped to a workplace must carry a label with specific information: a product name, a signal word (“Danger” for more severe hazards, “Warning” for less severe ones), hazard statements describing the nature of the risk, precautionary statements explaining how to handle the chemical safely, supplier information, and one or more standardized pictograms.
The pictograms are red-bordered diamond shapes, each containing a symbol that represents a category of danger:
- Flame: Flammable materials, self-heating chemicals, and those that emit flammable gas
- Flame over circle: Oxidizers that can intensify a fire
- Exploding bomb: Explosives and self-reactive chemicals
- Gas cylinder: Gases stored under pressure
- Corrosion: Chemicals that cause skin burns, serious eye damage, or corrode metal
- Skull and crossbones: Chemicals that are acutely fatal or toxic
- Health hazard (person with starburst on chest): Long-term dangers like cancer risk, organ damage, or reproductive harm
- Exclamation mark: Irritants, skin sensitizers, and less severe acute toxicity
- Environment: Aquatic toxicity (this one is not mandatory under OSHA)
Safety Data Sheets
A safety data sheet, or SDS, is the detailed backup document for every hazardous chemical. Chemical manufacturers and importers are required to create one for each product and send it along to any employer who purchases the chemical. Employers must keep these sheets accessible to workers during every shift. They follow a standardized 16-section format so that anyone trained on one SDS can navigate any other.
The sections move from the most immediately useful information to more technical details. The first three sections cover product identification, hazard classification, and chemical ingredients. Sections 4 through 8 address what to do in practical situations: first aid, firefighting, spill cleanup, safe handling and storage, and what protective equipment to use. The remaining sections cover physical properties, stability, toxicology data, ecological information, disposal, transportation, and regulatory status. Workers don’t need to memorize all 16 sections, but they should know how to find the information they need quickly.
Training Requirements
Employers must train workers on hazardous chemicals at the time of their initial assignment, not days or weeks later. Training is also required whenever a new chemical hazard is introduced into the work area. OSHA does not mandate a specific retraining schedule, but training must be effective, meaning workers need to actually understand the material.
The training itself must cover four things. Workers need to learn how to detect the presence or release of a hazardous chemical in their area, whether through monitoring equipment, visual signs, or smell. They need to understand the physical and health hazards of the chemicals around them. They must know what protective measures are available, including work practices, emergency procedures, and personal protective equipment. And they need a clear explanation of the labeling system and safety data sheets so they can use both independently.
Responsibilities by Role
Chemical manufacturers and importers carry the heaviest burden under HazCom. They must evaluate every chemical they produce or bring into the country, classify its hazards, create labels, and prepare safety data sheets. Distributors are responsible for making sure labels and data sheets travel with the product to whoever buys it.
Employers who simply use chemicals in their workplaces have a different set of obligations. They don’t need to classify chemicals themselves, but they must build and maintain a written HazCom program, keep a current list of hazardous chemicals on site, ensure containers remain properly labeled, make safety data sheets available to workers, and provide effective training. If an employer transfers a chemical into a secondary container for use, that container generally needs a label too.
The 2024 Update
OSHA published an updated version of the Hazard Communication Standard on May 20, 2024, aligning it with a newer revision of the Globally Harmonized System (GHS), the international framework that standardizes chemical classification and labeling worldwide. The original 2012 update adopted the third revision of GHS. The 2024 rule moves to the seventh revision, which improves label clarity, updates classification criteria, and better aligns U.S. requirements with those of Canada and other federal agencies.
Compliance deadlines for the updated standard were originally set to begin in January 2026, but OSHA extended them by four months in January of that year. Chemical manufacturers, importers, and distributors now have until May 19, 2026, to evaluate certain substances under the new criteria, with other deadlines shifted by the same four months. During the transition period, companies can comply with the previous version, the updated version, or both.
Penalties for Noncompliance
HazCom consistently ranks among OSHA’s most frequently cited standards. Common violations include missing or incomplete written programs, inadequate training, unlabeled containers, and inaccessible safety data sheets. As of January 2025, a serious violation carries a maximum penalty of $16,550 per instance. Willful or repeated violations can reach $165,514 per violation. Failure to fix a cited problem can cost $16,550 for every day past the deadline. For a workplace with multiple chemical containers or multiple untrained employees, these numbers add up fast.