Cyanide poisoning: effects on cells, and antidotes

A. It is my non-professional idea that cyanide kill you by attaching itself to the red blood cells with an extremely tight bond. This prevents oxygen from bonding at that site. Alcohol does a similar thing, but it is hard to immediately kill yourself with it because it is not as tight a bond and dissipates at the rate of 1 oz per hour (that is why people pass out when drunk -- lack of oxygen to the brain.)

A. Your best bet would be to research this topic through an occupational health site. The literature I have read suggests the copper itself causes few problems in relation to the cyanide as the compound disassociates internally. The cyanide will bind up the ATP at the mitochondrial level; I think the target organs will depend a great deal on the exposure level and route.

A. Mr. Dunleavy,

Cyanide antidote kits are what the EMT's and hospital will use if someone is exposed (along with the O2 of course). To my knowledge there isn't a viable alternative. It would be borderline criminal not to have an antidote kit handy if there is the possibility of exposure.

A. Try your local OSHA office or go to their site at WWW.OSHA.GOV they will be able to send you some info; or try your local poison control center, they also could be very helpful.

I recently read an article in one of the current issues of the AESF magazine about cyanide poisoning in a plating shop in Indiana. I was always under the assumption that the antidote for cyanide poisoning was Amyl Nitrite and according to this article it said sodium thiosulphate ⇦this on eBay or Amazon [affil links] they had used for the antidote. I know in our plating we still use a lot of cyanide our plating baths and I know the antidote shot we have is Amyl Nitrite that is what was recommended to us from our company's doctor. Maybe somebody could shed some light on this for me and point me in the right direction?

A. The amyl nitrite (street name "poppers") is an inhalation therapy. It's the first step in a protocol in which, as I recall, injection of another chemical is a second step. The full details are in The Canning Handbook [on eBay, Amazon, AbeBooks affil links].

As for the amyl nitrite, I don't think it is widely considered an appropriate treatment by the medical community anymore; I believe they currently feel that administration of oxygen is safer and better. But you need to acquire it anyway because OSHA fines people for not having it. Whether you should or shouldn't administer it is something I won't hazard a guess about, but perhaps your company doctor will advise.

The second step, injection, is something that only qualified medical personnel can do! Readers shouldn't even think about it. The reason to have it on hand is for the EMTs and the emergency room doctors.

There was a very scary story in P&SF if it is an accurate transcription of the events. A patient, believed by the rescue squad to have suffered cyanide poisoning, did not get treatment from the rescue squad and was allowed to die ... but his death may well have actually been from a heart attack, with no cyanide involvement at all. We'll never know because the coroner refused to perform an autopsy because of his perception of great danger in doing so.

This is yet another reason that a hydrogen cyanide detector is vital: so that, hopefully, a heart attack victim in a facility that uses cyanide will get treatment if the alarm doesn't ring.

A. The agreed correct procedure in the UK is to administer oxygen and get immediate medical help. Under no circumstances should anyone start injecting potential patients with anything unless they are medically qualified. It is easy to inject an air bubble into the blood system and that will definitely kill the patient. Furthermore, if someone does give an injection, the patient or their next of kin could successfully sue for assault. The cyanide antidote kit is there ONLY for the use of qualified medical personnel. I know it sounds hard, especially if your work mate has possibly been exposed to cyanide, but, regrettably, it is a fact of life - the only thing you can do is try to sustain life with oxygen so the experts can do their job. By the way DO NOT give mouth-to-mouth resuscitation; if you have a ventilating mask with a non-return valve in it, use that. As long as the patient is conscious, keep them calm; if they stop breathing and lose their heartbeat, then start CPR, but NOT m-t-m.

A.
"For many years HSE has received numerous enquiries relating to the treatment of cyanide poisoning, although incidents involving significant cyanide exposure are, fortunately, very rare. The amount of activity generated for both HSE and employers has appeared quite out of proportion to the risk. Most enquiries have related either to the appropriateness of various antidotes or to methods of resuscitation of victims of cyanide poisoning. The high level of interest has arisen from two causes. The first is the past recognition of cyanide as a 'specific hazard' requiring additional training for first aiders as described below. The second is that there has been much debate about the value of the various treatments, both first aid and medical, used for cyanide poisoning, with conflicting opinions coming from HSE, manufacturers and other authorities.

Previous attempts to standardise HSE's position and advice on first aid treatment for cyanide poisoning have been hampered by the regulatory framework. The Health and Safety (First Aid) Regulations 1981 made provision for additional training for first aiders, beyond the basic qualifications approved by HSE, 'as may be appropriate in the circumstances'. The 1990 Approved Code of Practice on First Aid at Work (COP 42) expanded upon this by stating, 'Where an undertaking presents specific or unusual hazards, then at least one of the suitable persons should have received additional or specialised training particular to the first aid requirements of the employers' undertaking'. One of the specific hazard situations defined in the associated guidance was where there was a danger of poisoning by cyanides or related compounds. Because of this a syllabus for training of first aiders in the treatment of cyanide poisoning was developed, mentioning the use of amyl nitrate ampoules and intravenous dicobalt edetate (Kelocyanor) as antidotes.

This syllabus had the status of guidance only and was never an absolute legal requirement, although employers were understandably reluctant to depart from its recommendations. Definitions of specific hazards have been dropped from the new revision of the first aid ACOP, and this has given HSE the opportunity to produce new, informal guidance. At the same time, the main manufacturer and supplier of cyanides in the UK was revising its safety data sheets. Its occupational medical department has more practical experience of treating cyanide poisoning than any other organisation in the country, so we had discussions with the company to establish a consensus view. As a result we have developed recommendations on the treatment of cyanide poisoning which are closely aligned with the information in manufacturers' safety data sheets.

ANTIDOTES FOR CYANIDE POISONING

Three antidotes for cyanide poisoning have been widely recommended for use in the UK, namely 'solutions A and B' (ferrous sulfate ⇦this on eBay or Amazon [affil links] dissolved in aqueous citric acid ⇦this on eBay or Amazon [affil links] , and aqueous sodium carbonate) given orally, amyl nitrate by inhalation, and intravenous dicobalt edetate (Kelocyanor).

The mixture of solutions A and B is only of value in reducing the absorption of swallowed cyanide, whereas the majority of accidental exposures are by inhalation or skin contact. The solutions also have a very limited shelf life. A recently published review of the use of this antidote has questioned the efficacy of the solutions and drawn attention to their inappropriate use. HSE is also aware of cases of iron poisoning where the solutions have been used incorrectly. This antidote should not be used.

Amyl nitrate, given by inhalation, has a long history of use in cyanide poisoning although there is little scientific evidence that it is of significant benefit. It is also potentially dangerous, particularly in people with some forms of heart disease, although serious illness caused by misuse seems to be rare. It can be abused by 'sniffers' and has to be obtained on a medical prescription. It also has a limited shelf life and can be difficult to obtain as it is manufactured only in small quantities. It use is still described in safety data sheets and there may be circumstances, such as the use of cyanide preparations in the field for control of rodents, where it is the only treatment which can practicably be given. HSE will not recommend its use, but would not object if particular employers, after conducting a risk assessment, decided to maintain a supply.

Kelocyanor, given by intravenous injection, has been proven to be of use when administered to seriously ill victims of confirmed cyanide poisoning. It is itself toxic, however, and can kill if used wrongly. HSE knows of several cases of inappropriate use resulting in hospital treatment. Its administration is beyond the scope of first aid and a recommendation has been made in the past that a 'Kelocyanor kit' should be kept by users of cyanide and transported to hospital with the patient. Unfortunately we are aware of cases where this has misled doctors to treat patients for cyanide poisoning when this diagnosis was not correct. Kelocyanor should only be used by medically qualified personnel when the diagnosis is certain and the patient is seriously ill. It should not be used by first aiders. HSE recommends that employers who use cyanides should discuss the arrangements for the medical treatment of cyanide poisoning with their local hospital or other provider of medical care. They should not routinely keep Kelocyanor at the workplace.

OVERALL OUTLINE OF FIRST AID TREATMENT FOR CYANIDE POISONING

Speed is essential. Obtain immediate medical attention. Protect yourself and the casualty from further exposure during decontamination and treatment. Inhalation: Remove patient from exposure. Keep warm and at rest. Oxygen should be administered. If breathing has ceased apply artificial respiration using oxygen and a suitable mechanical device such as a bag and mask. Do not use mouth to mouth resuscitation. Skin contact: Remove all contaminated clothing immediately. Wash the skin with plenty of water. Treat patient as for inhalation. Eye contact: Immediately irrigate with water for at least ten minutes. Treat patient as for inhalation. Ingestion: Do not give anything by mouth. Treat patient as for inhalation.

The conclusion is therefore that HSE will no longer recommend the use of any antidote in the first aid treatment of cyanide poisoning and will not require employers to keep supplies.

ADMINISTRATION OF OXYGEN AND ARTIFICIAL RESPIRATION

There is a great deal of anecdotal evidence of the value of oxygen and the experience of most occupational physicians is that the majority of victims of mild to moderate cyanide poisoning improve rapidly when treated with oxygen alone. There is also some evidence from animal studies that oxygen improves the response to treatment with specific antidotes. HSE will in future advise that administration of oxygen is the most useful initial treatment for cyanide poisoning. This implies that in premises where cyanides are used at least one person should be trained to administer oxygen. If breathing has stopped artificial respiration is essential. In the past, safety data sheets have advised that mouth-to-mouth resuscitation should not be used, because of the possible risk of secondary poisoning to the first aider, but no positive advice has been given on alternative methods. Manual techniques of artificial respiration are extremely inefficient and can not be recommended, so a suitable mechanical resuscitation device, through which oxygen can be given, is needed. The simplest solution is a bag and mask device connected to an oxygen supply. Other types of equipment could be used but in all cases the employer will have a responsibility to ensure that the first aider is trained to use the device.

REFERENCE
Nicholson P J, Ferguson-Smith J, Pemberton M A et al, 1994 Time to discontinue the use of solutions A and B as a cyanide 'antidote', Occup. Med. 44:125-128

By Richard Elliot, Technology and Health Sciences Division, HSE This article originally appeared in issue 29 of TSB (Toxic Substances Bulletin), January 1996.

FURTHER INFORMATION
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A. Cyanide poisoning is pretty terminal. I do not know of any evidence to show it is accumulative, so there shouldn't be a problem there. However, if you do exceed a lethal dose, you will die pretty quickly unless you can be given an antidote. I would strongly suggest you do not inhale anything from around a cyanide plating tank. If your employer is any good, he will use the safest systems available and thereby avoid putting you in danger. The minimum requirement for handling or working with any cyanide should be adequate extraction and adequate personal protective equipment for yourself. You must obviously also employ excellent personal hygiene practices.

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A. The good news is that cyanide is not considered a cumulative poison. It is present in lima beans (10 pounds is a fatal dose, they joke), apple pips, almonds, apricots, etc. But don't take my urban legend as fact; instead go to http://sis.nlm.nih.gov/Chem/ChemMain.html and select "ChemIDplus Advanced" and then enter "cyanide" in the first blank on the page, under Substance Identification [Thanks to Tom Gallant for this great reference].

The bad news is that cyanide is an extremely powerful, very quick acting, acute poison that has killed people in plating shops before, and probably will again. In addition to not ingesting it (a very small amount will kill you), the most important thing to remember is to not acidify it: that releases HCN gas, and that's what they do in the gas chamber. If you use anything (like powdered acid salts) that could possibly be confused with cyanide powders and allow mixing of cyanide with acid, that needs the strictest possible attention. Obviously cleaning out a tank or a floor spill is another case where acidification is possible.

In brief, I wouldn't worry about chronic continuous exposure myself, but would be very concerned about the possibility of accident. Just a personal opinion.

A. "Steam and condensate" normally are not carriers of the ionic compounds that are in the bath, unless they are mixed with mist or fumes that might be liberated from the bath during plating. Normally, it's just water, however it cannot be ruled out that there could be some carrier ions in it.

Your company safety and health representative, as well as your safety training required by OSHA, should contain sufficient information to allow self assessment of any symptoms you might have. The best place to look for that information would be in the OSHA required MSDS logs that must be at available to all employee's. If they don't have them available, then make a point of telling them do. Its a pricey fine to not have them. Usually they need to be available in employee access areas, in the front offices or ingress areas, and also at an external location accessible to emergency personnel.

A. Sean,

I work in a plating shop just loaded with cyanide. Never had a cyanide related health problem in the 14 years I've been here. Proper training on accidental acidification and handling is crucial, but just breathing the tank fumes has caused no problems. I would disagree with Mr. Baker about the possibility of cyanide in the fumes from the tank. As you are probably aware, plating produces some gassing at the anode and cathode. These little bubbles pop when they hit the surface of the tank. This tends to release a bit of tank aerosol containing whatever the solution is made of. I'm a chemist and I've tested this (just for kicks), also you can probably smell it when you go home and shower if you've spent a lot of time on the line. It is always a good idea to limit exposure so try to avoid prolonged stays by the tanks, but I wouldn't go nuts worrying about it.

Good Luck!

A. If you are greatly bothered by being around cyanide, you should quite probably find more suitable employment. Toxicity is in the dose. If your facility is not being grossly stupid, there is no problem in smelling a faint almond odor around the tanks. The level is nowhere enough to be fatal or even long term health hazard. Cyanide poisoning works just like alcohol poisoning, it ties up the hemoglobin (iron) in the red blood cell to a point that it retards the bloods ability to carry oxygen to the brain. Cyanide is a lot slower than alcohol to leave the blood stream, however. Enough cyanide or alcohol and you have little or no oxygen getting to the brain and you die. So, how much is enough of either. That in part depends on each individual.