Dilution Control and Labeling Standard

Purpose

This procedure guarantees that the liquid in a bottle on a cart is the strength its label calls for and that anyone who picks it up can tell what is inside. Three failures follow from skipping it. Two are dilution drift running in opposite directions. A dispenser drifting rich burns finish off VCT, hazes glass, leaves a tacky quat film that holds soil, and doubles chemical consumption. A dispenser drifting lean produces a disinfectant with no legal kill claim at all, because an antimicrobial diluted past its label rate is not the registered product any more and the shop is certifying a clean it did not perform. The third is what the labeling half prevents: an unmarked bottle used on the wrong surface, mixed with something incompatible, or drunk from.

Nobody catches either drift by looking. A 25 percent rich neutral cleaner looks exactly like a correct one in the bottle.

Scope

Covers every concentrate diluted at the shop bench or through a wall-mounted proportioner, every secondary container that leaves the bench, and the return of a dispenser to service after a tip change.

Does not cover concentrate PPE and the mix-station build, owned by the chemical mixing PPE protocol SOP on this shelf, and does not cover choosing a different product when the usual one is short, owned by the product substitution and SDS check SOP. Sealed ready-to-use products skip this procedure and go straight to the label.

What "1 to 64" means here

In U.S. janitorial practice a dispenser tip marked 1:64 is charted at 2 fl oz of concentrate per gallon of finished solution: 128 fl oz in a gallon divided by 64 is 2, so the 64 counts total parts of finished solution, not parts of water added to one part concentrate. Read the other way, one part in 64 parts water is 128 divided by 65, or 1.97 fl oz, which nobody will measure apart from 2.00.

It matters at strong ratios. At 1:8, total-parts gives 128 divided by 8 is 16.0 fl oz per gallon; parts-of-water gives 128 divided by 9 is 14.2 fl oz, about 11 percent apart. This shop states every rate in fl oz per gallon of finished solution and never as a ratio alone. Where the label states the rate its own way, transcribe the label's number rather than your conversion of it - label directions are what the reader is held to.

Roles and responsibilities

Procedure

Step 1 - Pull the current label and the SDS before touching the concentrate. Read the dilution rate, the intended use sites, and, on an antimicrobial, the contact time. Acceptance: the rate is written on the bench sheet in fl oz per gallon of finished solution, and the SDS section 8 glove material is named. What wrong looks like: a bench chart in pump strokes, or a rate you remember rather than read. Stop rule: if the container's own label is missing or unreadable, the container is not diluted from - tag it "UNKNOWN, DO NOT USE", keep it closed, and route it to the supervisor. Hazard at this step: none, the container stays closed and this is reading done at the bench; if it is already open, cap it before you read.

Step 2 - Put on the PPE the SDS names, then set up the measurement. You need a graduated concentrate reservoir and a container calibrated in fl oz. Acceptance: splash goggles or face shield, gloves of the SDS section 8 material, sleeves down, apron on, and an eyewash reachable in about 10 seconds of unobstructed travel, roughly 55 feet on level ground, in the ANSI/ISEA Z358.1 edition your employer follows, with 29 CFR 1910.151(c) behind it. What wrong looks like: nitrile on a solvent or oxidizer job because nitrile is what was in the box. Stop rule: no reachable eyewash, no concentrate handling at that bench. Hazard: concentrate contact and eye splash on the pour, plus an inhalation route on acids and hypochlorites - keep the container below face height, cap on until you pour, and if a splash lands, flush at the eyewash for the full duration the label states and give the SDS to whoever treats it.

Step 3 - Draw a measured volume and record what the concentrate side lost. Fill to a whole number of gallons, three where the reservoir allows it, because one gallon puts the reading inside the noise of a single air burp in the pickup tube. Read the reservoir before and after to the nearest 0.1 fl oz. Acceptance: two readings at 0.1 fl oz resolution, same reservoir, same sight level. What wrong looks like: a pickup tube lifting out of the concentrate part way through, which reads lean and is not the tip's fault. Stop rule: tube lifted, discard the reading and re-run topped up. Hazard: the discharge is live solution under line pressure, so keep your hand out of the stream, and if the outlet spits back, close the water supply before you look at it rather than reaching in.

Step 4 - Compute the delivered rate and compare it against the gate. Divide concentrate drawn by gallons drawn to get fl oz per gallon of finished solution, and show the division on the sheet rather than the answer alone. Acceptance: within 10 percent of the label rate, evaluated on the whole draw, not on a per-gallon guess. What wrong looks like: right on a 1 gallon draw and wrong on a 3 gallon draw, meaning the tip meters unevenly and both readings are suspect. Stop rule: outside 10 percent, the dispenser goes out of service with a tag naming the delivered rate and the date, and the route hand-mixes with a graduated cup until it is re-verified. Hazard: none, this is arithmetic at the bench with the containers closed.

Step 5 - Shut the water supply and relieve the line before any tip change. Close the supply valve feeding the dispenser and open the outlet to drop line pressure before you unscrew anything. Acceptance: the outlet runs dry and the tip comes out without resistance. What wrong looks like: a tip that fights you, which means the line is still pressurized. Stop rule: still pressurized after the outlet is open, stop and get the supervisor, because a check valve is holding and cracking a fitting on a pressurized line sprays concentrate rather than dilution. Hazard: face shield stays on for this step, and if concentrate does spray, the response is the step 2 eyewash flush, not a wipe with a rag.

Step 6 - Restore the supply, re-verify one draw, then return the dispenser to service. Open the supply valve you closed in step 5, watch every disturbed fitting for 30 seconds of running flow, then repeat steps 3 and 4 on a fresh three gallon draw. Acceptance: no drip at any disturbed fitting and a delivered rate inside 10 percent; the tag comes off only when both hold. What wrong looks like: a dispenser back on the wall, tag gone, no second draw recorded. Stop rule: fails the second draw, it stays tagged and the route stays hand-mixed. Hazard: this step puts water pressure and live chemical back into a system you opened, with your face at the fitting - stand to the side of the outlet, open the valve slowly, goggles on until the flow runs clean.

Step 7 - Label every secondary container before it leaves the bench. The label carries the product identifier as it appears on the shipped container, words or symbols conveying at least the general hazard, the dilution date, and initials. Acceptance: every bottle on the cart legible at arm's length and matching its contents. What wrong looks like: a bottle relabeled by crossing out the old name, or a food or beverage container used for chemical, which is how the ingestion event happens. Stop rule: an unlabeled bottle is handled as unknown per step 1 and is never emptied, combined or poured to a drain by whoever found it. Hazard: 29 CFR 1910.1200(f) permits the shorter workplace label only while the full shipped label and the SDS stay available on shift - if the binder or the electronic access is down, the shipped container comes to the job instead.

The record this produces

One line per dispenser position per verification, in the equipment log: date, dispenser position, product identifier, label rate in fl oz per gallon, gallons drawn, concentrate drawn, delivered rate with the division shown, pass or fail against the 10 percent gate, tip changed yes or no, second-draw rate where a tip was changed, initials.

The bottle carries the other half: identifier, hazard wording, dilution date, initials. A tech who finds a bottle older than the shelf life the label gives for the diluted solution dumps nothing and asks; some quats hold for weeks in an opaque bottle and lose activity in days in a clear one on a sunny van shelf.

A complaint about hazed glass or stripped finish months later is answerable in one line if the delivered rate was recorded, and unanswerable if it was not.

Worked pass: verifying a wall dispenser before a Monday route

Product is a neutral floor cleaner. The label rate reads 2.0 fl oz per gallon of finished solution.

Draw: reservoir read 32.0 fl oz before, 24.5 fl oz after, on a 3.0 gallon fill. Concentrate drawn is 32.0 minus 24.5, which leaves 7.5 fl oz. Delivered rate is 7.5 divided by 3.0, which is 2.5 fl oz per gallon.

Step 4 gate: within 10 percent of 2.0 fl oz per gallon is a band of 1.8 to 2.2. Delivered 2.5 against target 2.0 is 2.5 divided by 2.0, or 25 percent rich. Step 4 fails and takes its stop rule. The dispenser is tagged with "delivered 2.5 fl oz/gal against a 2.0 label rate" and the date, and the two carts leaving that morning are hand-mixed with a graduated cup.

Cause found at step 5: the tip was the degreaser position's, put back in the wrong hole after a cleaning. Supply closed, outlet opened, tip pulled dry, correct tip fitted.

Step 6 re-verification: reservoir 30.0 fl oz before, 24.0 fl oz after, on a 3.0 gallon fill. Concentrate drawn is 30.0 minus 24.0, which leaves 6.0 fl oz. Delivered rate is 6.0 divided by 3.0, which is 2.0 fl oz per gallon, on the label rate and inside the 1.8 to 2.2 band. No drip at the disturbed fitting over 30 seconds of flow. Tag comes off.

Self-check with the figures beside the criteria: rate in fl oz per gallon of finished solution both times (2.0 label, 2.5 then 2.0 delivered); gate evaluated on the whole draw, not per gallon (3.0 gallons both times); step 5 isolation restored and verified at step 6 (supply reopened, 30 seconds of flow watched, second draw run).

Exceptions you will hit

Concentrate short and the route leaves in twenty minutes: hand-mix from a graduated cup at the label rate and record it as hand-mixed. Never run a rich mix to stretch one bottle across two.

Customer's own dispenser at their site: verify it and report the delivered rate, but changing a tip on equipment you do not own needs their written authorization first. Until you have it, hand-mix and hand them the number you measured.

Diluted product left at the end of a route goes back on the shelf with its date where the label allows a shelf life, and to the disposal route SDS section 13 names where it does not. Never into a different bottle, never into a bottle that already holds something.

References

• 29 CFR 1910.1200, Hazard Communication, including the labeling requirements at (f) and the safety data sheet requirements at (g)
• 29 CFR 1910.151(c), medical services and first aid, for drenching and flushing facilities; ANSI/ISEA Z358.1 in the edition your employer or authority having jurisdiction follows, for the travel-distance and flow criteria
• The product's own shipped label and its safety data sheet, sections 8 and 13, which govern the dilution rate, glove material and disposal route
• See related: cleaning-chemical-mixing-ppe-protocol for concentrate PPE and the mix-station build; cleaning-product-substitution-and-sds-check for approving a different product; cleaning-disinfectant-contact-time-verification for what happens after the dilution is right