How to maintain an accurate chemical inventory

What the inventory has to support

Under OSHA's Hazard Communication Standard, 29 CFR 1910.1200(g)(1), an employer must have a safety data sheet in the workplace for each hazardous chemical it uses. An inventory that lists every product by the name on its SDS is the simplest way to show that each one has a matching sheet.

EPCRA Sections 311 and 312 apply to any facility that is required to maintain SDSs under the OSHA regulations for hazardous chemicals stored or used in the workplace, once a chemical is present at or above its reporting threshold. Section 311 asks for the SDSs, or a list of the chemicals, within three months of a chemical first reaching its threshold. Section 312, the Tier II inventory report, is due by March 1 each year and covers the previous calendar year. Both are based on the maximum amount present at any one time during the year, and Tier II also asks for the average daily amount and the number of days on site.

So an inventory that only records what was there on the day someone counted it is not enough. It needs to show where each product is, how the quantity changed through the year, and which SDS it belongs to.

Set up the inventory: the fields and a sample record

Start with one row per product per storage location. A product kept in two rooms gets two rows, so you can total it by room and by facility. If you are starting from scratch, a chemical inventory template with a field guide and fictional sample rows saves you designing the columns yourself.

Whatever tool you use, record enough to identify each product, find it and total it:

For mixtures, keep the SDS section 3 ingredient list (components, CAS numbers and concentrations) linked to the product, because EPCRA counts some components across every product that contains them.

Record every change, not just the annual count

An inventory counted once a year is out of date the next day. Keep it current by recording the events that change it, as they happen:

• Receipts: add containers to the receiving location when a delivery is accepted, and check that the product has an SDS on file before it goes to the floor.
• Transfers: move the quantity out of one location and into the other in the same entry, so the facility total does not change and nothing is counted twice.
• Usage: reduce the quantity at the location where the product was used or consumed.
• Disposal: remove containers that are emptied or shipped off site as waste, and note the date.
• New products and new locations: add a row, link the SDS and set the unit before the first quantity is entered.

Each entry should carry a date and the name of the person who made it. That history is what lets you rebuild the year's maximum later.

Keep units consistent

Containers arrive in gallons, liters, pounds and kilograms, but EPCRA thresholds are in pounds. Keep the container's own unit for counting, and add a pounds figure for totals.

• Convert liquids to pounds with the density or specific gravity from section 9 of the product's SDS, and write down the basis (for example, 4 x 55 gal x 7.3 lb/gal).
• For compressed gas cylinders, use the net contents weight rather than the cylinder size.
• Use one spelling for each product and each location everywhere, so totals do not split across near-duplicate rows.
• When a supplier issues a revised SDS with a different density, recheck the conversion on every row for that product.

A worked inventory update

Here is one product tracked through a month at a fictional facility with two storage locations: a Warehouse and a Paint room. The product, Example Solvent 100, is fictional, and so is its density of 7.3 lb/gal.

Reconcile quantities by location

Reconciliation means counting what is physically in each location and comparing it with the records, then correcting the records with a note. It catches unrecorded usage, lost transfers, duplicate rows and products that arrived without anyone adding them.

Reconcile at least before the Tier II report is prepared, and whenever a new process, building or product line starts.

Maximum quantities and facility totals

For EPCRA, three counting rules decide whether the inventory gives the right answer:

• Use the maximum amount present at any one time during the year, not an average and not the amount on the day you count.
• Total every location. The threshold applies to the facility, so a product stored in several rooms is added up across all of them.
• Count Extremely Hazardous Substances (EHS) inside mixtures. Multiply the component's concentration by the mixture's weight and add the result to all other quantities of that EHS at the facility at any one time. A hazardous chemical in a mixture need not be counted at 1% or less, or 0.1% or less if it is a carcinogen.

The federal thresholds are 10,000 lb for most hazardous chemicals and, for an EHS, 500 lb or the Threshold Planning Quantity, whichever is lower. Retail gas stations have separate thresholds for gasoline (75,000 gal) and diesel (100,000 gal) held entirely in compliant underground tanks. Check your state's instructions for any additional requirements.

Keep SDS associations current

Every inventory row should point to the SDS it was checked against. When the names match exactly, you can confirm that each product has a sheet, pull hazard categories and ingredients for reporting, and spot rows whose SDS has been replaced.

• Use the product identifier and manufacturer exactly as they appear on the SDS.
• Record the SDS revision date on the row, and update it when a revised sheet arrives.
• When a product is discontinued, keep its record and history instead of deleting it.
• Flag rows with no matching SDS and resolve them before the next report.

An ongoing maintenance workflow

A simple rhythm keeps the inventory reliable without a scramble every February. Whether you keep it in a spreadsheet or in chemical inventory software, the workflow is the same:

1. As changes happen: record receipts, transfers, usage and disposal with the date and who made the entry.
2. When a new chemical arrives: link its SDS, set its unit and conversion basis, and check whether it pushes a facility total toward a threshold. Section 311 has a three-month clock from the date a chemical first reaches its threshold.
3. On a regular cycle you set: reconcile each location against the shelf using the checklist above.
4. When an SDS is revised: update the revision date, and recheck density and ingredients.
5. Before the March 1 Tier II deadline: confirm each product's maximum amount, average daily amount and days on site for the previous calendar year, and have someone other than the preparer review the totals.

Moving an inventory into NeoTech, and reports out

If you use NeoTech's Product Inventory, each facility has one inventory batch per reporting year. There are two ways to build the list, and the reports come out once the list is certified:

• Guided Add: enter the manufacturer and product name, use Find SDS to match it to a workspace SDS, then add locations, container size, unit, count, storage type, temperature, pressure and days on site.
• Spreadsheet import: Download Template, then Upload CSV / XLSX (.csv, .xlsx or .xls, up to 25 MB and 5,000 rows). Columns are matched to inventory fields automatically, only Manufacturer Name and Product Name are required, and the imported rows replace the draft's list for you to review in the editor; nothing is recorded until you click Save.
• Find All and Calculate: Find All matches SDSs to every row by manufacturer and product name and shows which are unmatched. Calculate works out the 302, 311 and Tier II decisions from the inventory and SDS data: it converts liquids to pounds using the SDS density, totals each chemical across every product, container and location at the facility, counts EHS components inside mixtures, applies TPQs and the mixture cut-off, and checks stricter state thresholds where they apply. It records each row's result and the reason.
• Certify and report: a named person certifies the batch, which locks it. For each facility and reporting year, the Report Center generates the 312 Tier II report as a PDF or T2S file, as well as 302 (PDF) and 311 (PDF or ZIP) reports.
• Filing: either file with your state yourself and upload the confirmation receipt, or use NeoTech's filing service, which submits the Tier II to the SERC, LEPC and fire department. Either way, the owner or operator certifies the report.

There is also an option to import a prior Tier II filing (.t2s). It opens the file so you can read last year's contents; it does not create facility, inventory or report records, so the current year's list still has to be built.

Common chemical inventory mistakes

• Recording the quantity on the day of the count instead of the year's maximum.
• Totalling by room but never by facility.
• Recording a transfer as an addition at the new location without removing it from the old one.
• Leaving out EHS components inside mixtures.
• Using the general 10,000 lb threshold for a chemical that is an EHS.
• Converting gallons to pounds without recording the density used.
• Listing products by internal nicknames that do not match their SDSs.
• Copying last year's list forward without a physical check.

Official sources

EPCRA hazardous chemical reporting, including thresholds and the mixture rules, is in 40 CFR part 370. The SDS requirement is in OSHA's Hazard Communication Standard, 29 CFR 1910.1200. States set their own submission procedures, so check your state's instructions through EPA's directory.