Risk of Spontaneous Combustion / Self Heating.
Standard fire policy excludes the risk of self heating / spontaneous combustion, fire directly caused by its ownheating / fermentation / spontaneous combustion through the following express conditions as incorporated in standard fire policy form.
Condition excluding self heating / spontaneous combustion
Fire Policy condition 5 (1) b read as under:
Loss and/or damage to property occasioned by its own fermentation, natural heating or spontaneous combustion (except as may be provided in accordance with condition 7F) or by its undergoing any heating or drying process.
7 (f): Unless otherwise expressly stated in the policy this insurance does not cover coal, against loss or damage occasioned by its own spontaneous combustion.
In both the above conditions there is one exemption that the exclusion against loss / damage occurred from selfheating / spontaneous combustion only applicable to that particular property in which that self heating / spontaneous first occurred. If fire spread out and damage property lying/fixed/stacked separately at distance or as another unit or in form of another stack or heap etc this exclusion shall not apply to that part of loss which shall be considered as loss caused by fire and considered to be within ambit of standard fire policy.
For example selfheating / spontaneous combustion occurred in a heap of oil cake. The fire so setup spread out due to air current or some other means and involved another heap lying separately which caught fire and damaged. Now such damage to 2nd heap of oil cake shall stand covered under standard fire policy.
Coverage of spontaneous combustion as additional peril
By paying additional premium cover may be granted against fire damage through spontaneous combustion by its own heating etc by deleting conditions 5 (1) b of standard fire policy. It is important to note that even after paying additional premium and insertion of required additional perils clause / endorsement in the policy only the loss occurred due to fire is covered. Loss occurred due to self-heating prior to its self ignition shall still be excluded.
Professional, competent and experienced surveyors therefore separate both the losses while making an adjustment of loss.
The spontaneous combustion clause as used by the underwriters to grant this type of cover is as under. Wording may change slightly which vary from underwriter to underwriter.
Spontaneous Combustion Clause
"It is hereby declared and agreed that this insurance covers loss of or damage to the insured property caused by its own spontaneous combustion, not with standing anything stated to the contrary in the printed conditions of the policy"
Definition of Self Heating / Spontaneous Combustion
Spontaneous combustion is the self-ignition of a material. Spontaneous combustion starts when oxidation occurs within a substance, which releases heat. If the heat does not escape from the material, and the temperature of the material rises above its ignition point, spontaneous combustion will occur.
In other words spontaneous combustion is self ignition caused by internal heating due to chemical reaction in some commodities / elements / substance etc by 3 recognized ways and i.e. by reaction with atmospheric oxygen or by action of microbiological activities or reaction with other substances like water etc. Vegetable fiber, grasses, coals, fishmeal, vegetable/animal fats, other oil bearing products, oil seeds, oil cakes, meals and greasy rags etc are susceptible to self heat and spontaneous combustion under certain conditions.
Oil cake / oil seeds stacks may self-ignite because of heat produced by bacterial fermentation of the stack including other large number of factors. The stocks of all type of oil seeds, oil cakes, meals, greasy rugs etc by its nature and inherent vice are susceptible to self-heating and spontaneous combustion. In presence of high moisture, hot / damp conditions, poor ventilation and suffocation due to storing of huge quantity of stock in one Godown especially in heap form the chances of self-heating increase. Transportation in rainy/hot/humid season adds up into the situation. Moisture promotes hydrolytic / enzymatic fat cleavage which then results in self-heating due to increased respiration.
High respiration range is noticed during survey proceeding when surveyors may feel suffocation inside the storage area of such stocks and has to rush out for inhaling fresh air. Few types of coal are susceptible to spontaneous ignition. Pyrophoric materials are substances which have an auto ignition temperature which is below room temperature. These materials may ignite spontaneously when exposed to air or water pyrophoric substance is a substance that ignites spontaneously, that is, its auto ignition temperature is below room temperature. Examples are iron sulfide and many reactive metals including Uranium, when powdered or sliced thinly. Pyrophoric materials are often water reactive as well and will ignite when they contact water or humid air. They can be handled safely in atmospheres of nitrogen or argon. Most pyrophoric fires should be extinguished with a class D fire extinguisher.
Differentiation between Ordinary Fire Loss and Loss due to Spontaneous Combustion
It is not an ordinary task for Surveyors. Only experienced, competent and skilled Surveyors shall be able to make differentiation between the two after examining large number of factors at site of loss.
Following factors may be brought under consideration to differentiate the fire damage by spontaneous combustion and by ordinary fire from external visible means.
1. Presence of electrical wiring / installation etc in the storage area as cause of fire.
2. Any evidence of any external source of ignition found at site.
3. Burning started from the bottom of stock or from surface to differentiate the internal fire or fire by external means.
4. Open ventilators if provide in store leading to entry of rain water into the Godown.
5. Any evidence of burning on the surface areas of stock to prove the loss from any external source.
6. Any evidence of spreading of burning available to prove that it started from any external source and then spread.
7. Evidence of long storage period would lead to self heating/sp. Combustion.
8. High temperature of bottom layers of stock.
9. Presence of any exposure hazard at site.
10. The pattern/evidence of burning supporting the idea of burning from any external source.
11. Evidence of any burning marks on the walls, floor, roof of the store.
12. Evidence of high rate of dampness present on the walls of godown and stocks.
13. Evidence of frequent labor activity in the godown leading to smoking etc.
14. Nature of storage. Whether it was in form of heap or in bags. Size of heap.
15. Samples to be tested for microbiological activities etc.
16. Presence of mould, insects, beetles etc.
17. Odor smell if present in the stock.
18. Eye-witness statements regarding pattern of burning and seat of fire as well as origin of fire.
19. Thorough examination of physical evidence after cutting lanes in the affected heap.
It is very important to differentiate if more than one heaps / stocks are involved whether all the stocks lying separately are affected by way of its own self heating / spontaneous combustion or selfheating / spontaneous occurred in one stock or heap and then fire so set up spread and involved other heap(s) or stock(s) to apply condition No: 5(1) b of standard fire policy. Separating both the losses is very tricky exercise and only a competent and experienced surveyor may be able to assess the loss in the stock damaged by self heating and fire / spontaneous combustion separately.
Prevention from Self Heating / Spontaneous Combustion
The threat of spontaneous combustion can be reduced by improving storage, packing and transit conditions. The carriage and storage of this kind of product demands special attention and caution due to inherent vice of the product which is highly susceptible to self-heat slowly in transit and or in store. It may also ignite spontaneously if it becomes wet, or if it contains an excessive proportion of un-oxidised oil, moisture, depending on the oil and moisture content of the stock/cargo, the store / ship may need to be equipped with facilities of carbon dioxide or inert gas into the holds. The storage conditions also require to be specially improved as far as ventilation, moisture, contamination factors are concerned.
Since un-oxidized oil is often present in seed cake etc, exposure to oxygen may produce a reaction which generates heat. Under normal circumstances the rate of oxidation is slow, although the process may accelerate if the product is loaded / stored at an elevated temperature and moisture.
Microbiological activity also causes to create similar situation. During this activity the oxygen is absorbed and carbon dioxide is released which causes rise in temperature. If excessive moisture is also present in the seed cake, self-heating may occur. In extreme cases the combination of a high moisture content and excessive oil residues may result in spontaneous combustion. The risk is magnified if the cargo/stock becomes wet during transit or during storage. It is witnessed that the building provided for storage of such type of products is not built in accordance with the required specification. Ventilation is of prime importance both during transit and storage. Temperature, water contamination, moisture are the key factors for damage control. Storage of cake in bulk quantities forming one huge heap is more susceptible to damage by self-heating and microbiological activities. The next risk is spontaneous combustion.
Damage by forming mold due to similar reasons may also be taken in to account while long storage and voyage are being considered. Storage or transit of oil cake in bags, specially the jute bags which provides ventilated storage conditions to the product is less susceptible to self-heating and subsequent spontaneous combustion. Using multiple holed wooden planks to be fixed on bricks leaving 4 inches of clearance from the floor providing platform for storing product in jute bags is the best way to maintain the quality of product for longer period of time. After every 10 feet of width 3 feet wide lanes should be left in the storage building which should also be equipped with the exhaust fans and dehumidifiers. Grilled spacers may also be put in heaps after every 10 feet of width in order to maintain proper ventilation and moisture control during long storage.
It is also essential requirement to take regular temperature / moisture readings of the cargo/heaps of product in stores at various depths and necessary steps to improve the conditions should immediately be taken. Contamination with other oily products of obnoxious cargoes should be taken care with.
The floor level of storage building should at least 2 feet higher than the highest level outside the building.
Oil cake and products susceptible to self heat are usually packed in jute bags for transit through rail/road unlikely in bulk during transit by sea. The prime cause of loss is rain if the goods is not properly protected during transit. Loading in open railway wagons should be avoided where as proper coverage of tarpaulin is provided during transit on trucks. Fire occurrence is very rare during transit by road or rail.
Variation in weight during shipment and arrival at destination may occur due to inherent vice of the subject matter. The cake may evaporate / absorb moisture contents during transit subject to the atmospheric and storage conditions.
Infestation may occur by long prior shipment storage or especially when the transit medium is itself infested. Mold damage may occur under certain conditions especially during storage.
Periodical temperature and moisture readings should be taken at varying depths in the hold and recorded. If the temperature of the cargo exceeds 55 C and continues to increase, ventilation to the holds should be restricted. If self-heating continues, then carbon dioxide or inert gas should be introduced. The seed cake should be kept dry.
An experienced store staff may feel any change of state in the stock of such products while passing through and smelling. They could sense the heat, moisture, suffocation entering in to the storage area and may adopt suitable measures to control the progress of decay.
The writer of this article has witnessed during his professional life as Insurance loss adjuster/surveyor that the stock especially oil cake, meal is kept forming a single huge heap in the store for a longer period to sell out during price escalation. The store locked once is then opened when needed without going in to monitoring the condition of store / stock periodically. Under these circumstances they deserve for any worst.
Professionally it is suggested to draft a set of Insurance warranties for regulating the storage of such products by the insurance companies.