Dangerous Chemical Used in Aircraft: Proseal 870 Sealant

Aircraft mechanics are using different kinds of chemical in their daily maintenance work. But sometimes due to pressure, they often disregard their own personal protection. What are the health consequences if this P/S 870 corrosion preventive sealant has been mishandled?

Pro-Seal 870 is widely used in almost all aircraft structural repair, faying and sealing application. It is a kit that comes in two parts: Part A (black) acts as a HARDENER and Part B (white) acts as a BASE COMPONENT. When mixed and applied between two mating surfaces, it stops corrosion and water from building up. But behind its corrosion prevention property lays the hazards that can affect our health and environment. What are these dangers?


Proseal 870 hardener has MAGNESIUM CHROMATE and X-HYDRATE, which are known to cause cancer both in humans and experimental animals. If spilled on the environment, the residue must be sprinkled with sodium thiosulfate to neutralize toxicity. Prolonged and repeated inhalation of chromate can cause bronchial carcinoma.

Its base component contains FORMALDEHYDE.  Workers who are highly exposed to this chemical are at great danger of acquiring leukemia and brain cancer.  It directly affects the blood and bone marrow thereby disrupting its natural function to produce healthy blood cells. It also promotes the growth of abnormal cells in the tissues of the brain.

Reproductive Toxicity

TOLUENE also acts as one of the primary ingredient of its base component . This reproductive toxicant alters the normal reproductive functions of the male reproductive system by changing the sperm shapes and decreasing its count. In female, it affects the length of pregnancy and increases the chance of birth defects. Research done in laboratory suggests that toxicity from lab rats can be passed up to two generations of birth.

Kidney/Liver Damage

Prolonged inhalation of magnesium chromate can enter the bloodstream through the lungs. It will eventually pass to the liver that will cause serious damage. Elevated SGOT / SGPT levels indicate that the liver is not functioning normally and some of this might attribute to this chemical entering through the skin, lungs or mouth. Overexposure can cause depression and kidney liver damage.

Gastro-Intestinal Irritation

Aircraft mechanics who have no habit of washing hands after working with Proseal 870 can accidentally ingest some of its cured substances resulting to abdominal discomfort, vomiting and nausea. This usually happens due to pressure especially if the aircraft needs to fly as soonest possible time.

Eye Itchiness/Damage

Repeated contamination of magnesium chromate to the eyes (even in tiny micro particles) can cause itchiness especially at  the lower conjunctival sac. This allergic reaction is called toxic or irritant conjunctivitis. Direct contact to the eyes with Formaldehyde can cause permanent eye damage or loss of vision. If suffering from eye irritation, blurred vision, redness and tearing after direct contamination, consult  a doctor immediately.

Chrome Sores

Chrome sores are external ulcers that could affect a broken skin (wound cut) once prolonged contact with Proseal 870 has been established. It starts as a pus forming a hard ring around the wound. It usually shows on the knuckles, fingers and forearms.

Perforation and Ulceration of Nasal Septum

Inhaling chemical such as Proseal 870 can cause septal perforation. Its irritating properties can destroy the thin tissue of the nasal septum that act as a wall separating the nostrils. As a result, an ulcer can develop infecting and irritating the nose, throat and respiratory tract.

What to do?

If you are an aircraft mechanic, chances are you cannot avoid constant and repeated exposure to this chemical. Always keep in mind that even though immediate effects are not that strong, delayed effects can be proven fatal. Wear eye goggles, chemical resistant gloves and organic vapor cartridge or air-supplied respirator at all times to avoid the seven dangers that this Proseal 870 can do to your health.  

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One Response to “Dangerous Chemical Used in Aircraft: Proseal 870 Sealant”
  1. Billy coleman Says...

    On September 18, 2010 at 8:38 pm

    Great article, well done. There needs to be alot more articles on the dangers of chemicals used in aircraft maintenance. It is a very deadly line of work and maintenance companys do not care about your long term health.

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