Incompatible chemicals are substances that react dangerously on contact — releasing heat, toxic gas, or fire. The core incompatible pairs are acids with bases, acids with cyanide or sulfide salts, acids with bleach, oxidizers with flammable solvents, and water-reactive materials with anything aqueous. Store each of these groups separately, in its own secondary containment, and never in a shared spill tray.

What chemicals should never be stored together?

This is the short list every receiving dock and chemical store should have posted. Each row is a pair that must not share containment, a shelf, or a spill pallet.

Keep this…	…away from this	What happens if they mix
Strong acids (sulfuric, hydrochloric, nitric, phosphoric)	Strong bases (sodium hydroxide, potassium hydroxide, ammonia solutions)	Violent exothermic neutralization; boiling, spattering, container rupture
Any acid	Cyanide salts	Releases hydrogen cyanide gas
Any acid	Sulfide salts	Releases hydrogen sulfide gas
Any acid	Sodium hypochlorite (bleach)	Releases chlorine gas
Ammonia or ammonium salts	Sodium hypochlorite (bleach)	Releases chloramine gases
Oxidizers (nitric acid, hydrogen peroxide, permanganates, chlorates, perchlorates)	Flammable solvents, oils, greases, paper, wood	Ignition or explosion; no external spark required
Concentrated nitric acid	Acetic acid, acetone, alcohols, other organics	Violent oxidation, possible detonation
Water-reactive materials (sodium and potassium metal, calcium carbide, acid chlorides, anhydrides)	Water, aqueous solutions, damp air	Rapid heat release and flammable or corrosive gas evolution
Concentrated sulfuric acid	Water added into the acid	Violent boiling and acid spatter — always add acid to water, never the reverse
Peroxide-forming solvents (tetrahydrofuran, diisopropyl ether, 1,4-dioxane)	Air and light over time; also distillation to dryness	Forms shock-sensitive peroxides that can detonate
Flammable solvents (acetone, ethanol, toluene, xylene, IPA)	Ignition sources, oxidizers, compressed oxygen	Flash fire; vapors travel to remote ignition sources

NOAA and EPA maintain the authoritative dataset behind these predictions in CAMEO Chemicals reactivity groups, which will predict the outcome for any two specific substances you enter.

Why does chemical segregation matter more than a locked cabinet?

Most storage incidents are not caused by someone deliberately mixing two chemicals. They are caused by a leaking drum, a cracked tote valve, or an over-full spill pallet that lets two spills find each other on the floor. A cabinet keeps material contained; segregation is what decides whether a small containment failure stays small.

That is the reason segregation is organized by hazard class rather than by alphabet, product line, or purchase order. Storing acetic acid next to acetone because both start with “acet” is exactly the failure mode segregation exists to prevent.

What are the main incompatibility groups?

Five groups cover most industrial inventories. Give each its own containment area.

1. Flammable and combustible liquids — solvents, alcohols, aromatics, ketones.
2. Oxidizers — nitric acid, peroxides, permanganates, chlorates, hypochlorites.
3. Acids — mineral and organic. Nitric acid is an oxidizer as well and is usually isolated from other acids.
4. Bases and caustics — sodium hydroxide, potassium hydroxide, amines, ammonia solutions.
5. Water-reactive and air-reactive materials — alkali metals, carbides, acid chlorides, anhydrides.

Toxics and compressed gases are commonly handled as a sixth and seventh area depending on the site.

How does OSHA regulate flammable liquid storage?

OSHA’s flammable liquids standard, 29 CFR 1910.106, sets both the classification scheme and the cabinet limits. The flammable liquid categories are defined by flash point and boiling point:

Category	Flash point	Boiling point
Category 1	Below 73.4 °F (23 °C)	At or below 95 °F (35 °C)
Category 2	Below 73.4 °F (23 °C)	Above 95 °F (35 °C)
Category 3	At or above 73.4 °F (23 °C) and at or below 140 °F (60 °C)	—
Category 4	Above 140 °F (60 °C) and at or below 199.4 °F (93 °C)	—

Under 1910.106(d)(3)(i), a single storage cabinet may hold no more than 60 gallons of Category 1, 2, or 3 flammable liquids, or no more than 120 gallons of Category 4 flammable liquids. Under 1910.106(d)(3)(ii), the cabinet must limit its internal temperature to no more than 325 °F during a 10-minute standard fire test, and must be labeled in conspicuous lettering: “Flammable — Keep Fire Away.”

Read the standard directly at OSHA 29 CFR 1910.106. Note that the cabinet is a quantity limit, not a segregation strategy — a compliant cabinet full of mixed hazard classes is still a bad cabinet.

How should you physically separate incompatible chemicals?

• Separate secondary containment. Each hazard group gets its own spill pallet or bunded area. Never share a spill tray between acids and bases.
• Separate cabinets, not separate shelves. A shelf above another shelf shares a spill path.
• Corrosives low. Store acids and caustics at or below waist height so a dropped container does not reach eye level.
• Nitric acid alone. It behaves as an oxidizer; keep it out of the general acid cabinet.
• Date peroxide formers. Mark the receipt and open date on THF, ethers, and dioxane, and dispose of them on schedule.
• Label the storage area, not just the drum. Segregation only survives staff turnover if the area itself is signposted.

Every decision above starts with the SDS. Section 7 covers storage and Section 10 covers incompatible materials — see how to read a safety data sheet and how to read a GHS label on a chemical drum. Segregation rules also need to appear in your written program — see what a hazard communication program is.

Which RightPath products need segregated storage?

Most of the catalog falls into one of the five groups above. A few common examples:

• Sodium hydroxide 50% solution — caustic. Never share containment with any acid.
• Acetone — flammable liquid. Keep away from oxidizers; see how to store acetone safely.
• Mineral and organic acids across the bulk acid line — segregate from caustics and from cyanide and sulfide salts.
• Solvents across the bulk solvent line — see is acetonitrile flammable? for a worked example.

Every product RightPath ships arrives with an SDS, and the full SDS library is public so you can build your segregation map before the truck arrives. For classification during transport rather than storage, see DOT hazmat classes for solvents.

How do you get segregation-ready documentation from RightPath?

Send your product list and RightPath will return the current SDS set along with an all-in quote. If you are consolidating suppliers, ask for the documentation package up front rather than after delivery. Request bulk pricing.

Frequently asked questions

What are the five basic groups of incompatible chemicals?

Flammable and combustible liquids, oxidizers, acids, bases and caustics, and water-reactive or air-reactive materials. Each group needs its own storage area and its own secondary containment.

Can you store acids and bases in the same cabinet?

No. Acids and bases react exothermically. If both leak into a shared spill tray, the reaction boils and spatters corrosive liquid. Acids and bases require separate cabinets with separate secondary containment.

Why can’t you store bleach with acid?

Sodium hypochlorite reacts with acids to release chlorine gas. It reacts with ammonia and ammonium salts to release chloramine gases. Both are acutely toxic by inhalation.

Is nitric acid stored with other acids?

No. Nitric acid is a strong oxidizer as well as an acid, and it reacts violently with organic acids such as acetic acid and with solvents such as acetone and alcohols. Store it isolated from both the acid group and the flammables group.

How much flammable liquid can be stored in one cabinet?

Under OSHA 29 CFR 1910.106(d)(3)(i), a storage cabinet may hold no more than 60 gallons of Category 1, 2, or 3 flammable liquids, or no more than 120 gallons of Category 4 flammable liquids.

Where can I check whether two specific chemicals are compatible?

Use the NOAA CAMEO Chemicals reactivity tool, which predicts the reaction between any two substances in its database, and cross-check Section 10 of each product’s safety data sheet.

A hazard communication program is the written plan OSHA requires every employer that uses hazardous chemicals to develop, implement, and maintain at each workplace under 29 CFR 1910.1200(e)(1). It must describe how the employer meets the standard’s requirements for labels, safety data sheets, and employee training, and it must include a list of the hazardous chemicals known to be present.

If an OSHA compliance officer walks into your plant, the written program is usually the first document requested. Everything else — container labels, the SDS binder or portal, training records — is checked against what the program says you do. This guide breaks down what the standard actually requires, document by document, and where your chemical supplier fits into the chain.

What must a written hazard communication program contain?

Under 29 CFR 1910.1200(e)(1), employers must develop, implement, and maintain a written program at each workplace. The standard names the elements it has to cover.

Required element	Citation	What it means in practice
How labels and other forms of warning are handled	1910.1200(e)(1)	Describes your workplace labeling system and who maintains it
How safety data sheets are handled	1910.1200(e)(1)	Describes how SDSs are obtained, stored, and made accessible
How employee information and training are handled	1910.1200(e)(1)	Describes training content, timing, and documentation
A list of the hazardous chemicals known to be present	1910.1200(e)(1)(i)	Uses the product identifier that appears on the matching SDS; may be site-wide or by work area
Methods for non-routine tasks and unlabeled pipes	1910.1200(e)(1)(ii)	Covers jobs like vessel cleaning and chemicals in unlabeled piping

The chemical list is where most programs fall apart. OSHA requires the product identifier on the list to match the identifier on the safety data sheet. If purchasing switches suppliers or grades and nobody updates the list, the list and the SDS library drift apart.

How must safety data sheets be kept?

OSHA requires the employer to maintain copies of the required safety data sheets for each hazardous chemical in the workplace, and to ensure they are readily accessible during each work shift to employees when they are in their work areas — 1910.1200(g)(8).

Electronic access is explicitly permitted. The standard allows electronic access and other alternatives to paper copies as long as no barriers to immediate employee access in each workplace are created by such options. A tablet on the production floor is fine. A PDF library that only the EHS manager can log into is not.

For employees who travel between workplaces during a shift, 1910.1200(g)(9) allows the safety data sheets to be kept at the primary workplace facility.

Learn how to read the document itself in our guide to the 16 sections of a safety data sheet.

What must a chemical container label include?

Labels on shipped containers are the supplier’s obligation. Under 1910.1200(f)(1), the chemical manufacturer, importer, or distributor must ensure each container of hazardous chemicals leaving the workplace carries six elements.

#	Label element	Citation
1	Product identifier	1910.1200(f)(1)(i)
2	Signal word	1910.1200(f)(1)(ii)
3	Hazard statement(s)	1910.1200(f)(1)(iii)
4	Pictogram(s)	1910.1200(f)(1)(iv)
5	Precautionary statement(s)	1910.1200(f)(1)(v)
6	Name, U.S. address, and U.S. telephone number of the manufacturer, importer, or other responsible party	1910.1200(f)(1)(vi)

Workplace labeling is a separate, looser requirement. Under 1910.1200(f)(6), each container of hazardous chemicals in the workplace must be labeled with either the full shipped-container information, or the product identifier plus words, pictures, or symbols giving general hazard information that works alongside the rest of your program.

Our walkthrough of how to read a GHS label on a chemical drum covers what each element looks like on a real drum.

What must hazard communication training cover?

Training is required at the time of initial assignment and whenever a new chemical hazard employees have not previously been trained about is introduced into their work area — 1910.1200(h)(1). The standard lists four minimum training topics under 1910.1200(h)(3):

• Methods and observations used to detect the presence or release of a hazardous chemical in the work area, such as employer monitoring, continuous monitoring devices, or visual appearance and odor
• The physical, health, simple asphyxiation, combustible dust, and pyrophoric gas hazards, plus hazards not otherwise classified, of the chemicals in the work area
• The measures employees can take to protect themselves, including work practices, emergency procedures, and personal protective equipment
• The details of the employer’s hazard communication program

Note the trigger: a new chemical hazard, not simply a new product. Swapping one acetone supplier for another does not trigger retraining. Adding a first aromatic solvent to a plant that previously ran only alcohols does.

Where does your chemical supplier fit in?

Three of the documents an auditor asks for originate upstream, with the manufacturer or distributor: the shipped-container label, the safety data sheet, and the certificate of analysis that ties a specific lot to a specific specification. A supplier that is slow with documents becomes your compliance gap.

Practical questions worth asking any distributor before you buy:

• Is the current SDS available without a login or a phone call?
• Does the product identifier on the SDS match the label and the invoice line?
• Is a certificate of analysis issued per lot, and does it reference the same identifier?
• Does the shipping paperwork carry the correct DOT hazard class and UN number for the material?

RightPath Industries maintains a public SDS library covering the chemicals we distribute, so EHS teams can pull current documents without waiting on a sales rep.

What grades and sizes do we stock?

RightPath Industries distributes more than 8,000 chemicals from our Pittsburgh headquarters, spanning acetates, acids, alcohols, aromatics, bromine chemicals, glycols, high purity analytical solvents, powdered chemicals and salts, and solvents. Common industrial solvents such as acetone ship in gallons, pails, drums, totes, and bulk, packed to your specification and lot-controlled on request.

How do you order from RightPath?

Send the product identifier, grade, packaging size, and destination, and we will return pricing with the documentation package attached. Request bulk pricing or call our Pittsburgh office to speak with a sourcing specialist.

Frequently asked questions

Is a written hazard communication program required for every workplace?

OSHA requires employers to develop, implement, and maintain a written hazard communication program at each workplace where hazardous chemicals are used, under 29 CFR 1910.1200(e)(1). The program is site-specific, so a company with three plants generally maintains three programs.

Can safety data sheets be stored electronically instead of in a binder?

Yes. 29 CFR 1910.1200(g)(8) permits electronic access and other alternatives to paper copies, provided no barriers to immediate employee access are created in each workplace during every work shift.

How often is hazard communication training required?

OSHA requires training at the time of initial assignment and whenever a new chemical hazard that employees have not previously been trained about is introduced into their work area, under 29 CFR 1910.1200(h)(1). The standard does not set a fixed annual interval.

Who is responsible for labeling a drum of solvent that arrives at my plant?

The chemical manufacturer, importer, or distributor is responsible for the label on the shipped container under 29 CFR 1910.1200(f)(1). Once the material is transferred to workplace containers, the employer is responsible for workplace labeling under 1910.1200(f)(6).

Does the chemical list have to match the safety data sheets?

Yes. 29 CFR 1910.1200(e)(1)(i) requires the list of hazardous chemicals to use a product identifier that is referenced on the appropriate safety data sheet.

A safety data sheet (SDS) is a 16-section document that a chemical manufacturer or importer must supply for every hazardous chemical it sells. The sections always appear in the same order, so you read an SDS by jumping to the section that answers your question: Section 2 for hazards, Section 4 for first aid, Section 8 for PPE and exposure limits, Section 14 for shipping classification.

That fixed order is the whole point. OSHA standardized it under the Hazard Communication Standard, 29 CFR 1910.1200, so an EHS manager, a receiving clerk, and an ER physician can each find what they need in seconds without reading the document front to back. This guide breaks down what lives in each section, which ones OSHA actually enforces, what changed under the 2024 HazCom update, and how to get current sheets from your supplier.

What is a safety data sheet, and who has to provide one?

Chemical manufacturers and importers must evaluate the hazards of the chemicals they produce or import and prepare an SDS for each hazardous one. Distributors must pass that SDS down the supply chain. Employers must maintain SDSs for every hazardous chemical in the workplace and keep them readily accessible to employees during each work shift.

Three timing rules govern the paperwork:

• A supplier must send the SDS with the first shipment of a product to a new customer.
• When an SDS is revised, the supplier must send the updated sheet with the first shipment after the revision.
• A manufacturer or importer must update an SDS within three months of learning significant new information about a chemical’s hazards or protective measures.

An SDS is not a certificate of analysis. The SDS describes hazards for a product family; the COA reports the tested results for one specific lot. Buyers in regulated industries need both — see our guide to reading a certificate of analysis.

What are the 16 sections of an SDS?

OSHA fixes the content and order in Appendix D to 1910.1200. Here is what each section holds and who typically uses it.

#	Section	What it tells you	Primary user
1	Identification	Product name, recommended use, supplier name, address, emergency phone number	Purchasing, receiving
2	Hazard(s) identification	GHS hazard classes and categories, signal word, pictograms, hazard and precautionary statements	Everyone
3	Composition / information on ingredients	Chemical identity, CAS numbers, concentrations or concentration ranges, impurities	EHS, toxicology
4	First-aid measures	Treatment by exposure route, symptoms, when to get medical help	First responders, medical
5	Fire-fighting measures	Suitable extinguishing media, specific hazards, protective equipment for firefighters	Fire brigade, EHS
6	Accidental release measures	Spill containment, cleanup procedures, personal precautions	Operations, EHS
7	Handling and storage	Safe handling practices, incompatible materials, storage conditions	Warehouse, plant
8	Exposure controls / personal protection	OSHA PELs, ACGIH TLVs, engineering controls, required PPE	EHS, industrial hygiene
9	Physical and chemical properties	Appearance, odor, flash point, boiling point, density, vapor pressure, particle characteristics	Engineering, process
10	Stability and reactivity	Chemical stability, conditions to avoid, incompatible materials, hazardous decomposition	Process safety
11	Toxicological information	Routes of exposure, acute and chronic effects, LD50/LC50, carcinogenicity listings	EHS, medical
12	Ecological information	Aquatic and terrestrial toxicity, persistence, bioaccumulation	Environmental
13	Disposal considerations	Waste handling and disposal guidance, container disposal	Waste, environmental
14	Transport information	UN number, proper shipping name, hazard class, packing group, marine pollutant status	Logistics, shipping
15	Regulatory information	Safety, health, and environmental regulations specific to the product	Compliance
16	Other information	Date of preparation or last revision, revision summary, abbreviation key	Document control

Which SDS sections does OSHA actually enforce?

This is the detail most SDS explainers skip. OSHA requires all 16 sections to appear so the format matches the global GHS standard, but OSHA does not enforce the content of Sections 12 through 15. Those sections cover ecological information, disposal, transport, and regulatory status — subject matter that falls under the EPA, the Department of Transportation, and other agencies rather than OSHA.

The practical consequence: Sections 12–15 are useful but not authoritative. If you are classifying a shipment, verify Section 14 against the DOT hazardous materials table rather than treating the SDS as the final word. Our breakdown of DOT hazmat classes for solvents walks through how UN numbers and packing groups are assigned.

Which sections should you read first?

Most people never need all sixteen. Match the section to the question you actually have.

Your question	Go to
Can this hurt someone, and how badly?	Section 2, then Section 11
What PPE does my team need?	Section 8
Is there an exposure limit I have to monitor?	Section 8
Can I store this next to that?	Section 7, then Section 10
Someone was exposed — what now?	Section 4
There is a spill on the dock.	Section 6
How do I ship or receive it?	Section 14
Is this sheet current?	Section 16

Section 16 deserves more attention than it gets. It carries the revision date, and a stale revision date is one of the most common findings in a HazCom audit. Check it before you file the sheet, not after the inspector asks.

What changed under OSHA’s 2024 HazCom update?

OSHA published a final rule on May 20, 2024 aligning the Hazard Communication Standard with Revision 7 of the UN’s Globally Harmonized System. It took effect July 19, 2024. The rule revised SDS Appendix D content in Sections 1, 2, 3, 8, 9, 10, 11, and 14, with the principal GHS-alignment changes falling in Sections 2, 3, 9, and 11.

Two changes matter most to buyers. First, trade-secret concentrations can still be withheld, but Section 3 must now disclose the concentration using one of OSHA’s prescribed ranges — you will no longer see a blank where a percentage should be. Second, Section 9 uses revised physical-property terminology and explicitly addresses particle characteristics.

On January 15, 2026, OSHA extended all HCS 2024 compliance dates by four months. The revised schedule:

Deadline	Who	What
May 19, 2026	Manufacturers, importers, distributors	Updated classifications, labels, and SDSs for substances
November 2026	Employers	Workplace labels, written HazCom program, and training for substances
November 2027	Manufacturers, importers, distributors	Updated labels and SDSs for mixtures
May 2028	Employers	Workplace labels, written program, and training for mixtures

During each transition window, either the 2012 or the 2024 version of the standard is acceptable. Source: OSHA, Final Rule to Amend the Hazard Communication Standard.

How the SDS connects to the drum in front of you

The GHS label on a container is a compressed version of SDS Section 2. Same pictograms, same signal word, same hazard statements — the label is the summary, the SDS is the full record. If a label and an SDS disagree, the SDS revision date tells you which one is out of date. See how to read a GHS label on a chemical drum for the label side of that pairing.

How do you get current SDSs from a distributor?

Ask before you buy. A distributor that cannot produce a current SDS on request is a distributor that will slow down your next audit. RightPath Industries, a Pittsburgh-based bulk chemical distributor supplying 8,000+ chemicals and recognized as a top-10 U.S. ethanol distributor, maintains a public SDS library so buyers and EHS teams can pull documentation without opening a support ticket. Lot-specific COAs ship with the order.

When you evaluate any supplier’s documentation, check four things: the SDS reflects the most recent significant hazard update, the revision date in Section 16 is legible, Section 3 discloses concentrations or OSHA-permitted ranges, and the emergency phone number in Section 1 is answered around the clock.

Browse the full bulk solvent product line, or work through the rest of our chemical guides. Ready to source? Request pricing and we will include documentation with the quote.

Frequently asked questions

How many sections does a safety data sheet have?

A safety data sheet has exactly 16 sections. The number, order, and headings are fixed by OSHA in Appendix D to 29 CFR 1910.1200 and match the UN GHS format used internationally.

What is the difference between an MSDS and an SDS?

An MSDS (material safety data sheet) was the pre-2012 U.S. format, which had no required section order and varied by manufacturer. OSHA replaced it with the 16-section SDS when it aligned HazCom with GHS in 2012. Any sheet still labeled MSDS is out of date and should be replaced.

Which SDS sections are most important for worker safety?

Section 2 and Section 8. Section 2 states what the chemical can do to a person, and Section 8 states the exposure limits and personal protective equipment required to prevent it. Section 4 is the third priority because it governs the response after an exposure occurs.

How often must a safety data sheet be updated?

There is no fixed calendar interval. A chemical manufacturer or importer must revise the SDS within three months of becoming aware of significant new information about the chemical’s hazards or ways to protect against them, and must send the revised sheet with the next shipment to customers who received the product in the prior twelve months.

Does an SDS replace a certificate of analysis?

No. An SDS covers hazard and handling information for a product as a whole and does not change lot to lot. A COA reports the measured test results for one specific production lot. Pharmaceutical, food, and laboratory buyers generally require both documents on every shipment.

Which SDS section has the flash point?

Section 9, Physical and chemical properties. That section also carries physical state, odor, pH, melting and boiling point, flammability, vapor pressure, relative density, solubility, and viscosity.

Which SDS section has the UN number and shipping name?

Section 14, Transport information. It lists the UN number, UN proper shipping name, transport hazard class, packing group, environmental hazards, and any special precautions. Section 14 is non-mandatory under OSHA, but virtually all suppliers populate it because shippers need it.

Can we keep SDSs electronically instead of in binders?

Yes. OSHA explicitly permits electronic access and other alternatives to paper copies, as long as no barriers to immediate employee access are created in each workplace. Employees must be able to reach the sheet during their shift, in their work area, without waiting for someone else.

Authoritative sources

• 29 CFR 1910.1200 Appendix D — Safety Data Sheets (Mandatory)
• 29 CFR 1910.1200 — Hazard Communication Standard

Need a quote? Request bulk pricing from RightPath Industries and receive the SDS and COA with your quote.