Exploding Sink Drains

Household chemicals can be every bit as dangerous as industrial strength materials. Most drain cleaning formulations are based upon very strong corrosive chemicals. The chemicals used can be either very concentrated acids or very strong caustic alkalis. In either case the mixing of these concentrated corrosives with water will generate substantial amounts of heat. Water on top of a plug in a drain trap can be an "accident waiting to happen". Pouring the drain cleaner into the water on top of the plugged drain can cause the water to heat and boil. The plugged drain and trap piping act like the barrel of a cannon if sufficient steam is generated, blasting scalding hot caustic up out of the drain. We have been presented with "commercial" drain cleaners which when analyzed proved to be concentrated acids. Thermodynamic calculations with estimates of "typical" water contents in a plugged sink drain indicated that heating and boiling could not occur. However when the amount of water was decreased in the theoretical model a limit was found below which the conditions for a steam explosion were met. Unfortunately this precis has been written because of the severe forearm burns received by an unsuspecting individual while using the "commercial" product according to the instructions on the label.

The printed instructions had been followed and a measured quantity of acid was added to a plugged drain which contained very little water. The water was heated and boiled so quickly that a "steam explosion" occurred and the drain pipe acted like a cannon barrel for the scalding hot acid.


Suntan and Massage Lineament Burns

We received a series of photos from a legal firm, which depicted at least second-degree burns to the upper back, and shoulders of a young lady. The burns had been received as a result of a sun tanning session, which had followed shortly after massage therapy that used a lineament to stimulate the skin and promote circulation.

The actual bottle of lineament used was unavailable but a new bottle of the product was provided for our examination and comment. The bottle was an offshore preparation and the ingredients were listed on the label.

The main solvent for the formulation was food grade ethanol or ethyl alcohol. Ethyl alcohol is a reasonably volatile chemical and will evaporate if the bottle is left open or inadvertently heated by sunlight. Evaporation of the solvent increases the concentration of the active ingredients thus changing the original formulation. Besides the oils and fragrances in the formulation the physiologically active components in the product were classified in the literature as "vesicants" literally "blistering agents". At proper dosages the active ingredients caused the blood vessels to dilate thus increasing the blood flow to the area of application. Excessive concentrations of the compounds were capable of producing chemical burns to the tissues contacted.

The effects of the sun tanning lamps upon the residual absorbed chemicals in the skin and the overall contribution of the ultra-violet radiation itself to the development of the burns are currently unknown.



Burns from Hair Colouring Chemicals

A selection of professional hair colouring chemicals were delivered to our office and we were asked to report on the types of problems, which might result from the incorrect use of these materials. It had been reported that normal use of these products had produced severe scalp and neck burns.

The primary task undertaken was to develop a chemical analysis method to analyze the delivered products to confirm that they had been correctly formulated. Normally the purity and quality of chemicals are tested before they are put into a formulation. It was necessary to develop and verify (validate) an analysis procedure for the mixed components before we were able to test the products. The formulation matched the composition claimed on the label and further investigation by the insurance adjusters found negligence on the part of the technicians using the product.