Burns: Thermal, Chemical, and Electrical

Why this matters

Burns on residential jobs come from torches, solder, hot flue pipe, steam and hot water, battery acid, drain openers, wet concrete and electrical faults. The first aid for them is simple and mostly about water, which is why it goes wrong in predictable ways: ice instead of cool water, thirty seconds under the tap instead of ten minutes, butter or ointment that traps the heat, a ring left on a hand that swells shut around it, and a chemical burn rinsed once and declared done. The other predictable failure is judging a burn by how much it hurts. Some of the worst burns hurt least.

This card covers the three kinds of burn a tech will meet, how they differ, and which ones go to an emergency department. It follows current American Red Cross and American Heart Association first aid guidance. It is not training: hands-on first aid certification is what makes a responder.

First, stop the burning

Every burn starts with ending the exposure, and the action depends on what is burning:

• Heat or flame. Get the person away from the source. Clothing on fire: stop, drop and roll, or smother with a blanket or jacket. Shut off the torch at its valves, not by setting it down lit.
• Hot liquid or steam. Remove soaked clothing quickly, because wet cloth holds the heat against the skin. Leave anything stuck to the skin where it is.
• Chemicals. Gloves on before you touch the person or their clothes, then brush off dry material and get contaminated clothing, gloves and jewelry off.
• Electricity. The source is turned off before anyone touches the person. See related: Electrical Shock First Response.

Thermal burns: cool, uncover, cover

Cool with cool running water, and keep going for at least 10 minutes. That is the figure current guidance gives, and it is longer than almost anyone does by instinct. Cooling does two things: it stops heat that is still in the tissue from burning deeper, and it reduces pain. A garden hose on a gentle flow, a sink, a shower or a bottle of clean water poured steadily all work. Ten minutes feels very long while you are doing it; use a phone timer.

No ice, no ice water, no butter, no ointment, no toothpaste. Ice damages already-injured tissue and can add a cold injury to a burn. Butter, oils and ointments hold heat in and have to be scrubbed off at the hospital.

Remove rings, watches, bracelets and tight clothing near the burn while cooling, before swelling makes it impossible. A ring left on a burned finger can cut off its blood supply.

Cover it loosely with a sterile non-stick dressing or a clean, dry cloth. Do not wrap tightly. Do not break blisters; they are a sterile cover the body built.

Keep the rest of the person warm. Cooling a large burn with water can chill the whole body, especially outdoors or on a cold slab. Cool the burn, not the person: a blanket over everything that is not being cooled.

Read the depth by appearance, not by pain:

The palm of the injured person's hand, fingers included, is about one percent of their body surface. It is the quickest field measure of how big a burn is.

Chemical burns: brush, strip, flush, and keep flushing

Chemical burns keep burning until the chemical is gone, so the first aid is removal, at volume, for a long time.

Brush off dry chemicals first. Dry lime, cement powder, dry drain-opener crystals and similar powders can react with water and heat up or concentrate. Brush them off with a gloved hand or a cloth, then flush.

Flush with large amounts of cool running water, and keep flushing. Guidance for chemical burns is to keep going until emergency responders take over, and the product's SDS (safety data sheet), section 4, often states a minimum, commonly 15 to 20 minutes or longer for strong acids and alkalis. Flush in a direction that runs the water off the person, away from the eyes and unburned skin.

Do not try to neutralize an acid with a base or a base with an acid. The reaction gives off heat and adds a second injury.

Two chemical burns behave differently from the rest:

• Wet concrete, mortar and grout are strongly alkaline, commonly cited at around pH 12 to 13. Alkali burns penetrate deeper than acid burns and often do not hurt for hours. The classic case is a worker who kneels in wet concrete, or gets it inside a boot, and finds the burn that evening. Wash off any skin contact promptly and change wet clothing, rather than waiting until it hurts.
• Hydrofluoric acid, found in some aluminum brighteners, rust removers, wheel cleaners and certain acid-based coil cleaners (check the SDS for hydrofluoric acid or bifluoride salts), penetrates the skin and damages deep tissue and bone, and can disturb the body's calcium badly enough to affect the heart. The pain may be delayed and out of proportion to what the skin shows. Flush, and go to the emergency department regardless of how it looks. The SDS for products containing it usually names a calcium gluconate gel as first aid; shops that use these products should keep it with them and know when to use it, and the ER still sees the person.

Chemical in the eye has its own procedure. See related: How to Flush an Eye After a Chemical Splash. And many of the same products are an inhalation hazard as fumes. See related: Inhalation Exposure First Response.

Electrical burns: the skin is the least of it

An electrical burn shows where current entered and left the body, often as a small gray, white or charred spot at each point. What it does not show is the heating along the path between them, through muscle, nerves and blood vessels, which can be extensive behind a small skin mark. That is why the rule is simple: every electrical burn goes to an emergency department, and one from any source above household voltage, or with any loss of consciousness, chest symptoms or confusion, is a 911 call. Cover the skin burns loosely with dry dressings; the treatment that matters is the medical evaluation. Arc flash burns are different again: they are heat burns from the arc's blast and can be large, and they come with eye and hearing injury.

Which burns go to the emergency department

Call 911, or go to the emergency department, for any burn that:

• causes trouble breathing, or came with signs of breathing in heat or smoke: singed nose hairs, soot around the nose and mouth, a hoarse voice, coughing;
• is full thickness, at any size;
• is partial thickness and larger than the person's palm;
• is on the face, hands, feet, genitals, or over a major joint, or wraps all the way around a finger, limb or the torso;
• is electrical, from an explosion, or from hydrofluoric acid;
• is chemical and the chemical is not known, or the burn is still worsening after flushing;
• is on a very young or elderly person, which matters when the burn is a customer's family member.

A small superficial burn, or a partial-thickness burn smaller than the palm and not on any of those areas, can usually be handled with first aid and watched, or seen at an urgent care clinic. See related: When to Go to the ER Versus Urgent Care.

A worked case: the drain hose that came off

A plumber is draining a tank water heater that is set well above its normal temperature, hot enough that the water steams as it leaves. The drain hose slips off the valve and very hot water sprays across the back of his left hand and wrist and soaks his sleeve.

Stopping the burn. His helper closes the drain valve with a gloved hand and a rag, standing to the side of the spray, then gets the plumber's wet sleeve pushed up and off the burn. Both took seconds and both mattered: a closed valve ends the exposure, and a soaked sleeve keeps burning.

Cooling. The helper gets the plumber's wedding ring off first, then runs a utility sink tap cool, not cold, over the hand and wrist and starts a 10-minute timer. Around the four-minute mark the plumber says it feels better and pulls his hand out. The helper puts it back under; the timer, not the feeling, decides when cooling ends. The plumber is standing in a cold basement, so the helper drapes a moving blanket over his shoulders.

Reading it. After cooling, the back of the hand is red with several blisters forming, wet and very painful: partial thickness. Measured against the plumber's own palm, the burned area is a bit larger than his palm, and it is on the hand.

The call. It meets two of the emergency-department criteria at once, partial thickness larger than the palm and on the hand. The helper covers it loosely with a non-stick dressing, does not break the blisters, and drives him to the ER, since he is alert, breathing normally and has no other injuries. With soot, a hoarse voice or a large full-thickness area, the helper would have called 911.

What changes the answer. A superficial burn on one knuckle, smaller than a coin, would get the same 10 minutes of cooling and a loose cover, and probably no hospital at all. The same spray onto his face would have been an emergency department visit at any size. And if the liquid had been a caustic drain opener instead of water, the response would have changed shape: gloves before touching him, flushing for the SDS's stated time or until responders arrive, and the product container going to the ER with him.

The failure this case avoids. Two of them, really. Pulling a burn out from under the water when it stops hurting lets heat finish burning deeper. And a ring left on a burned hand turns into a tourniquet as the fingers swell.

References

• American Red Cross and American Heart Association, current first aid guidelines on thermal, chemical and electrical burns.
• The product's safety data sheet, section 4 (first-aid measures), for chemical-specific flushing times and antidotes.
• CDC/NIOSH guidance on hydrofluoric acid exposure.
• See related: Electrical Shock First Response; Refrigerant and Cold Contact Burns.
• See related: How to Flush an Eye After a Chemical Splash; The First-Aid Kit for a Service Van.