Wet Concrete Skin Contact and Burn Prevention

Purpose

A cement burn does not hurt while it is happening. That single fact is what makes this the injury that takes knees off working crews: wet concrete against skin runs strongly alkaline, commonly pH 12 to 13 once cement meets water, and an alkali injury saponifies tissue and keeps going inward while the worker feels nothing worse than damp. The pain arrives hours later, usually at home, by which time a contact that would have rinsed off in two minutes is a full-thickness burn needing debridement and sometimes a graft. Nobody stops work for a wet knee, so this procedure removes the judgment call: barriers issued and inspected before the truck, flush water at the work, and any contact flushed on a clock rather than on how it feels.

Scope

Covers protection, flush response and post-contact handling for skin and eye exposure to fresh concrete, grout, mortar, slurry and washout water on residential and light commercial work, for every person on the pour including the driver and any customer standing near it.

It does not cover the airborne route from cutting or grinding cured concrete, owned by the silica dust control SOP, nor sealers, curing compounds and form release, whose hazards route to their own SDS. One boundary is worth naming: OSHA's chromium(VI) standard at 29 CFR 1926.1126 expressly excludes exposures to portland cement, so the hexavalent chromium in cement, a real skin sensitizer, is managed here through the SDS and barrier protection rather than under that standard.

Roles and responsibilities

Procedure

1. Issue and inspect the barrier before the shift, worker by worker. Hand out waterproof boots tall enough for the deepest placement that day, alkali-resistant gloves with a cuff past the wrist, long sleeves and trousers, and sealed eye protection for anyone within splash range of a chute, pump or vibrator. Acceptance: every item present and intact, boots with no split seam, gloves with no pinhole, checked by inflating and holding. Wrong looks like a torn glove kept because the pour starts in ten minutes, which routes concrete straight to skin and holds it there; stop rule, worn or holed items are replaced before that worker enters the placement area, and with no spare they work outside splash range.

2. Seal the openings, because that is where the burns happen. Trousers go over the boot top, never tucked in; sleeve cuffs go over the glove cuff, taped where a worker reaches into a chute or works overhead. Acceptance: no gap at boot top, wrist or waist when the worker crouches and reaches, checked in that posture rather than standing. Wrong looks like a trouser leg tucked into a boot, which turns the boot into a reservoir holding concrete against the shin for the rest of the pour; stop rule, re-dress before entering the pour. Hazard: taped cuffs slow removal, so the tape is a single wrap that tears by hand, never wound so it has to be cut off.

3. Set the flush station at the work, not at the truck. Provide clean water in volume within seconds of the placement area plus a plumbed or portable eye flush unit, both charged and unfrozen. Acceptance: 29 CFR 1926.50(g) requires that where the eyes or body may be exposed to injurious corrosive materials, suitable facilities for quick drenching or flushing are provided within the work area for immediate emergency use, so acceptance is a unit inside the work area with its seal intact and enough water for 15 to 20 minutes of continuous flushing. Wrong looks like relying on the mixer's wash-down hose, which leaves with the truck; stop rule, no placement begins without the station, and it stays until the last washout is done. Hazard: the station is itself a trip and a freeze point, so it sits clear of the buggy run and out of the sun.

4. Kneel on a barrier, and change position on a clock. Anyone kneeling on fresh concrete uses waterproof knee protection over impervious trousers, and the crew leader calls the position change rather than leaving it to the worker. Acceptance: no fabric-to-concrete contact at the knee, and a stated interval at which finishers stand, check and re-seat pads. Wrong looks like a pad slid up the thigh with the trouser knee wet and dark, the exact presentation that becomes a debrided knee; stop rule, wet fabric against skin means leaving the slab and running step 6 now, not at the end of the panel. Hazard: pads change footing on a floating surface, so the worker stands before turning rather than pivoting on the pad.

5. Rinse as you go, and never dry-brush set splatter off skin. Keep a rinse bucket at the finishing station and clear splatter from forearms, wrists and neck as it lands. Acceptance: no dried film on skin at any break, hands and forearms rinsed and dried before eating, drinking or using the toilet. Wrong looks like a crew that rinses at the end of the day, by which point the alkali has had six hours against the wrist under a sleeve; stop rule, splatter inside a glove means removing the glove and flushing, and the glove goes back on only after it is rinsed inside and out. Hazard: dry-brushing set splatter abrades skin and lifts dust, so it is wetted and wiped rather than scrubbed, and dust from cured material routes to the silica SOP.

6. Flush a skin contact on the clock, not on pain. Strip the contaminated boot, glove or clothing immediately, including anything soaked underneath, and flush with clean running water for at least 15 to 20 minutes continuous. Acceptance: material fully removed, flushing timed rather than estimated, and skin re-examined afterward for redness, blistering or a soft glazed look. Wrong looks like 30 seconds under the hose because it does not hurt, which is the reported course of nearly every serious cement burn; stop rule, blistering, broken skin, or contact that sat more than a few minutes goes to medical care the same day with the SDS in hand, and that worker does not return to the pour. Hazard: never apply vinegar, citrus or any acid to neutralize an alkali burn, because the reaction is exothermic and adds a thermal injury; water only, and remove rings early since fingers swell.

7. Treat an eye splash as an emergency before anything else. Flush at the eye unit with lids held open, continuously, for at least 15 to 20 minutes, and move toward emergency care while flushing continues if a portable unit allows it. Acceptance: continuous irrigation for the full period with the eye rolled through its full range, and a hand-off to medical care in every case, not only where vision is affected. Wrong looks like stopping when the grit feeling passes, since alkali keeps penetrating the cornea after the sensation eases; stop rule, no judgment branch here, every eye splash goes to medical care. Hazard: contact lenses trap material against the cornea, so they come out as flushing starts, and nobody drives themselves.

8. Check skin at the end of the shift and record what happened. The crew leader asks each worker directly and looks at knees, shins, wrists and the small of the back where a belt holds a wet shirt. Acceptance: a yes or no per worker, any contact logged with duration, area and flush time, and a follow-up call next morning to anyone who reported one. Wrong looks like announcing "anyone hurt?" to a group, which reliably returns silence; stop rule, new pain, redness or blistering overnight goes to medical care that day. Hazard: none in the check itself, but treatment beyond first aid makes the case recordable on the OSHA 300 log under 29 CFR 1904.7, so the office logs it rather than deciding it was minor.

The record this produces

Two records. A daily pre-pour PPE and flush-station check listing each worker, items issued and condition found, plus the station location and confirmation it was charged. And a contact report carrying worker, time of contact, what contacted what, how long before flushing began, flush duration, skin condition after flushing, the referral decision and the next-morning follow-up.

Both live on the job record with the safety file. The crew leader reads the check sheet next morning to see which boots to replace. The owner reads the contact reports across a quarter, and contacts clustering on one task, kneeling during float work or reaching into a pump hopper, is a task to re-engineer rather than workers to re-train. The office needs the report for the OSHA 300 determination, and the timing fields are what a clinician asks for first.

One pass, with a step that failed

A three-person crew, footings and a 5 in interior slab. Step 1 issued boots, gloves, sleeves and eye protection to all three and pulled one pair of gloves with a thumb pinhole found by inflating them. Step 3 put a 20 gallon fresh water drum and a sealed portable eye unit at the slab edge, six paces from the working face.

Step 4 failed during float work. A finisher's left knee pad had ridden up as he worked backward across the panel, and his trouser knee had been against fresh concrete for about 40 minutes before the crew leader saw the dark patch on the fabric. The stop rule ran: off the slab immediately, trouser leg cut away rather than pulled over the wet area, 20 minutes of continuous flush from the drum timed on a phone. The skin came up red across roughly a palm's area with two small blisters at the kneecap, so under step 6 he went to urgent care that afternoon with the SDS. Diagnosis was a partial-thickness chemical burn, dressed, no debridement, light duty for four days.

The number that matters here is time, not area. Contact ran about 40 minutes against a flush that began about 2 minutes after discovery, so the tissue sat in a pH 12 to 13 environment for roughly twenty times as long as it took to stop it once anyone looked. Nothing in the worker's own experience would have prompted that flush, since he reported no pain before the blisters formed. That is why step 4 sets a called position change instead of asking finishers to notice, and why step 8 asks each worker individually.

What the crew changed came out of the contact report rather than a meeting: knee pads strapped above and below the joint instead of one strap, and the position change called at each panel edge, which puts eyes on the fabric every few minutes.

When the situation does not match the procedure

Contact happens where there is no running water, on a remote footing pour or after site water is shut off: bottled drinking water goes to the eyes without hesitation, the drive to care starts immediately, and flushing continues on the way. A worker refuses care because it does not hurt: that is the normal presentation of an alkali burn, so the shop sends them and the office calls in the morning either way. The person exposed is a customer or a driver rather than an employee: the flush is identical, and the shop's duty here is the ordinary duty of care rather than an OSHA duty, so flush, get them to care, and tell the office the same day. Concrete gets inside a boot with no spare on the truck: that worker leaves the placement area and works dry.

References

• 29 CFR 1926.50(g), medical services and first aid, requiring quick drenching or flushing facilities within the work area where eyes or body may be exposed to injurious corrosive materials.
• 29 CFR 1926.1126(a), chromium(VI) in construction, for the express exclusion of portland cement exposures from that standard.
• 29 CFR 1904.7, general recording criteria, for when medical treatment beyond first aid makes a case recordable.
• The safety data sheet for the specific cement or ready-mixed product in use, which carries the pH, the sensitization statement and the first-aid instruction a clinician will ask for.
• See related: the silica dust control SOP for the airborne route from cutting and grinding, and the ready mix delivery SOP for washout slurry handling.