Sweet but not so innocent

They might seem fairly innocuous, but sweets can represent a real choking hazard. Three scientists from LGC let us in on what tests sweets go through before being let on to the UK market The little boy was five years old and enjoying chatting and sharing jokes with the adults when he choked on a fruit gel snack. Paramedics were called and on arrival they found no pulse and removed a 1.5cm piece of gel from his throat. After resuscitation in the local Accident & Emergency Hospital, the boy’s normal heart beat and pulse were regained but tragically, despite intensive care, he was pronounced brain dead three days later1.

These stark facts conceal depths of human tragedy most of us can only guess at and, although many children survive choking, it is a significant cause of death amongst children. In the UK there were approximately 24 choking fatalities a year in the under fours between 1986 and 19952. More recently the picture has improved slightly – nine children aged under five years died as a result of choking in 2007. But asphyxia (through accidental choking, strangulation or suffocation) is the third most common cause of accidental death in UK children after road traffic accidents and house fires. Each year in the UK over 15,000 children under five and a further 10,000 children aged between five and 14 are treated at A&E after choking.

We describe here some specific work carried out by LGC under the Government Chemist Programme to help improve methods of testing for choking hazards of food origin, specifically, jelly mini-cups.

About half of all choking accidents in young children involve food, with sweets and fish bones being the most frequent causes. Other frequently aspirated objects include peanuts, meat (hot dog and burger fragments), while non-food choking objects include balloons and coins. In the 1986-1995 study, toys accounted for only a small proportion of cases but recently the number of cases involving toys has increased. Toys found in food, batteries, buttons and uninflated balloons can also cause choking and should be kept away from very young children3.

Foreign bodies lodged in the oral cavity, pharynx, or larynx can produce airway obstruction leading to hypoxia, respiratory failure, or even cardiac arrest. If lodged in the trachea or main stem bronchus the foreign body may remain there leading to inflammation and pneumonia, chronic infection, or abscess formation.

Children under three years are particularly vulnerable to choking caused by a foreign object as they often put objects in their mouths. Their teeth, trachea and bronchi are small and full control of the muscles of their mouth and throat has not yet developed. Young toddlers do not have a fully developed ability to chew, swallow and time these actions with breathing4.

In 2003, reports started to emerge of a new choking risk – jelly mini-cups and dome shaped jellies consumed in a single bite. The original products contained ‘konjac’ E425, a glucomannan, which is difficult to dissolve. Following the reported fatalities due to these sweets lodging in the throats of children and elderly people, several EU Member States took measures to prohibit temporarily the importation and sale of all jelly mini-cups. LGC was called in to carry out analyses of the products and supplied information to the Food Standards Agency and the European Food Safety Authority (EFSA) which issued a report in July 20045. As a consequence, the European Commission went on to propose an extended ban on a range of gel-forming additives.

The ban was initially introduced by way of an addition to the introductory note to Annex I of Directive 2006/52/EC of the European Parliament and of the Council of 5 July 2006. This effectively banned a list of gel forming additives in jelly mini-cups. The legal definition of a jelly mini-cup was given as “jelly confectionery of a firm consistence, contained in semi-rigid mini-cups or mini-capsules, intended to be ingested in a single bite by exerting pressure on the mini-cups or mini-capsule to project the confectionery into the mouth.” The obvious problem with this definition lies in deciding, forensically, just what ‘firm consistence’ really means when applied to a jelly!

LGC’s expertise in this area stems in part from work undertaken by its Food Chemistry and Consumer Safety teams. LGC’s Food Chemistry team provides a comprehensive range of analytical, research and consultancy services for industry and public sector organisations, encompassing food, fertiliser and feed chemistry, composition, authenticity, safety and legislative compliance. The team benefits from a unique combination of knowledge and experience including chemists, food scientists, molecular biologists and statisticians coupled with relevant legislative knowledge.

The Consumer Safety team provides technical advice and support to Government on regulatory chemical issues related to the safety of consumer products. This covers a wide range of consumer products but is especially concerned with the most vulnerable members of society and in particular children. The work involves participation in British and European standardisation committees to develop safety standards in support of legislation. The team also benefits from extensive experience in the investigation of consumer products where specialised analysis is required, including nitrosamines in cosmetic products and latex rubber, phthalates in plasticised materials and organo-tin compounds in non-woven materials.

LGC remains the host laboratory of the Government Chemist’s statutory responsibilities under certain Acts of Parliament for providing independent analytical measurement and expert opinion to help avoid or resolve the disputes over scientific data which arise from time to time between local authorities and the businesses that they regulate.

Therefore, when the Government Chemist was called in to adjudicate a dispute between an importer and a Port Health Authority (PHA) on the exact interpretation of the definition of a ‘jelly mini-cup’ LGC’s Food Chemistry and Consumer Safety teams played a key role in the investigation.

The Public Analyst for the PHA had concluded that the consignment of jelly mini-cups fell within the legal definition and should not be allowed entry to the UK, but the importer had obtained expert opinion that the consignment satisfied legal requirements. The casework was conducted to the usual forensic standards starting with a case meeting to select the analytical strategy, rigorous chain of custody of evidence and all significant analytical steps witnessed by a second scientist. The final report was drafted with input from a forensic pathologist, reviewed by a qualified person (MChemA) and finally peer-reviewed by the Government Chemist.

LGC’s scientists followed an analytical strategy based on the work carried out by LGC in 2004. Briefly, the products were described, photographed, measured, weighed, tested for size in relation to a ‘small parts cylinder’, tested for solubility, compression and force needed to penetrate. The compression and penetration testing was performed using a Hounsfield H10K-S Materials Testing Instrument with a 500N test cell. We found that the samples under investigation gave lower compression and penetration results than the specimens from LGC’s 2004 tests. However, our findings still supported the proposition that the products might be viewed as ‘firm’ within the meaning of the legal definition. Size and weight are important parameters and our findings were that the samples, removed from their containers and patted dry, measured 27-32 mm in diameter across the base and 41-48 mm in overall height. They typically weighed between 15.5-18.3 grams. All the suspect items fitted into a standard small parts cylinder (diameter 31.7 mm, long side 57.1 mm, short side 25.5 mm) when introduced point first, but they just failed to fit the cylinder if introduced base first.

The key test was when the jellies were then immersed (and shaken) at 37°C in specially prepared standard artificial saliva. The scientists found that the products retained their essential shape and structure for at least 45 minutes, whereas a prepared ‘domestic’ jelly formed in the empty container of the product dissolved in under two minutes. If an object lodged in the airway causing total blockage does not dissolve within a short critical time period, asphyxiation will result in tissue anoxia that will cause irreversible brain damage and/or death.

LGC’s testing process also considered the strength of a child’s grip between finger and thumb based on an extensive dataset of such information published by the former DTI6.

It was common ground between the parties to the dispute that the products contained E407 carrageenan, one of the banned additives. The question remained, however, if the consignment conformed to the legal definition. Part of the answer to this question was that it was clear that the consignment consisted of jelly confectionery contained in semi-rigid mini-cups. It was also clear from the size and weight that the products could be ingested as a single bite by exerting pressure on the container.

Added to this, although the products were very easily bitten through, they were not readily soluble in artificial saliva. Given this, and the fact that the items were self supporting and relatively firm after compression, LGC’s scientists concluded that the products could be regarded as ‘firm’ within the meaning of the definition given in the Regulations.

LGC presented its evidence to all the parties involved in the dispute. Our conclusions were accepted and the consignment was destroyed.

Full experimental details and a considered analytical strategy were subsequently written up and submitted to the peer-reviewed journal Food Analytical Methods, providing both trade and official laboratories with readily available tools to predict if a choking risk is presented. If a risk is determined, the product can then be swiftly prevented from coming onto the UK market. It is considered vital that an opinion on these sorts of product should only be arrived at with the benefit of laboratory examination.

In a post-script to our work, it’s interesting to note that progressively larger versions of jelly mini-cups have since been brought onto the market in an attempt to make the products too large to lodge in a child’s airway and thus safer.

References:

1. A USA case report, Qureshi, S. and Mink, R., 2003, Aspiration of Fruit Gel Snacks, Pediatrics, 111, 687-689, and references therein.
2. Department of Trade and Industry, DTI. 1999 Government Consumer Safety Research, Choking risks to children under four from toys and other objects, URN 99/708 Available at http://www.berr.gov.uk/files/file25392.pdf 
3. Child Accident and Prevention Trust, Choking accidents factsheet. www.capt.org.uk and http://www.tradingstandards.gov.uk/kent/documents/AE%20factsheets/Choking%20factsheet.pdf
4. http://www.bbc.co.uk/health/physical_health/conditions/choking2.shtml
5. Anton, R, Barlow, S, Boskou, D. et al., 2004, Opinion of the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food on a Request from the Commission related to the use of certain food additives in Jelly mini cups. The EFSA Journal 82, 1-11 (and references therein) available at
6. http://www.efsa.europa.eu/cs/BlobServer/Scientific_Opinion/opinion_afc14_ej82_jelly_minicups_en1.pdf?ssbinary=true
7. Norris B and Wilson J R. CHILDATA;  The Handbook of Child Measurements and Capabilities Data for Design Safety, DTI  June 1995 ISBN 0 9522 571 1 4

Contact: w: www.lgcgroup.com e: michael.walker@lgcgroup.com