2.3 Fibreglass vessels

The construction of fibreglass vessels takes its name from the materials that are most commonly used in their construction: fibreglass and polyester resin. These materials are well known for their strength and the ease with which they can be worked, as well as for their cheapness. More expensive substitutes, like carbon fibre and phenol resin, do exist however and can be used to create a product with different characteristics. The risk analysis which follows also applies to different types of fibre and resin other than fibre glass and polyester resin.

 

2.3.1 Conventional risks in the construction of fibreglass vessels

The generally limited size of fibreglass boats makes “conventional risks” of little importance. The heavier objects to be moved are moulds, engines and on-board plant. Those parts that have to be moved in order for work to be carried out on them are almost all lightweight.

Ladders and scaffolding used in construction are generally limited in height and falls rarely exceed three metres.

There is only limited use of machines for bending, cutting and joining and little use of other machine tools.

There is a risk of falling objects during movement of moulds, when the wheelhouse is placed on the hull to be glued and in the fitting-out stage, when the propellers, machinery and on-board equipment are loaded.

 

2.3.2.Specific risks in fibreglass construction

The main risk is of exposure to organic vapours during the creation of the hull and wheelhouse (involving spreading of fibreglass sheets and resin). The most common organic vapour from polyester resin is styrene. If another type of resin is used it will produce another type of vapour and the relevant safety table should be consulted for further information.

Exposure to organic vapours also happens when the moulds are prepared using wax and polyvinyl alcohol.

The gel-coat which is spread on the mould before beginning the operations with the sheets and resin has a composition similar to resin and therefore is not a source of new specific risk.

Gluing operations use different types of glue which emit small quantities of solvent and present a risk to workers.

The risk of exposure to the following items is still present, even if to a lesser degree than in shipbuilding:

 

·          solvents in painting operations

·          welding fumes when welding tubes and other metal parts

·          oil vapours during testing of the engines

There is a risk of exposure to noise, but much less so than in shipbuilding.

2.3.3 Risk of serious incidents in fibreglass construction

The use of large quantities of resin and organic compounds causes a serious risk of fire and explosion.

Free flame must not be used when working on the moulds.

If a fire or explosion happens in a closed or restricted area, for example during fitting-out, it can cause serious damage.

2.3.4 Risks to the health of workers in fibreglass vessel costruction

2.3.4.1 Risks

Risks to the health of workers in fibreglass boatyards come from exposure to harmful substances such as styrene and different types of alcohol and polyphenol.

Table 5 shows the activity/risk matrix for activities giving rise to specific risks. 

Table 5 - Activity/risk matrix for activities giving rise to specific risks in the costruction of fibreglass boats

 

The information in the table is not sufficient to evaluate the risks connected with welding, as it would be necessary to identify the harmful agent and its effect on the respiratory system and the other organs of the worker.

In the case of polyester resin, which is most commonly used in boat construction, the substance present in the air inhaled by the workers is styrene. The relevant safety table will contain a description of the harmfulness of this substance. If a phenol resin made up of an aromatic polyoxydrilic compound and an aliphatic alcohol is used, the composite substance present in the air is alcohol and to a lesser extent polyhydric alcohol. The safety data sheet contains a description of the harmfulness of this substance.

The risk of inhaling harmful organic substances is also present when the moulds are prepared. The mould is wetted with polyvinyl alcohol or an equivalent substance and spread with wax to facilitate the removal of the cast from the mould when it has hardened.

The gel-coat which is spread on the prepared surface has a composition similar to resin and therefore is not a source of other types of risk.

The same considerations made in paragraph 2.2.4.1 apply to painting and cleaning activities, although once again they are less important in fibreglass construction than in shipbuilding.

The solvents contained in the paint and the soaps contained in the detergents must be identified, together with the information contained in the relative safety tables.

Trimming of the products and cutting of the sheets creates resin and fibreglass (or carbon fibre) dust. These are considered to be inert substances.

It should be noted that fibreglass construction became popular when the dangers of asbestos were well known. It is therefore not probable that repairs or conversions will involve the removal of asbestos insulation.

Welding is most commonly undertaken in the fitting-out stage when tubes are joined and the plant is assembled.

2.3.4.2.Health protection measures

The greatest risk of inhaling harmful substances occurs when the hull and wheelhouse are being manufactured, as these activities use the greatest quantity of material for the longest time.

For small boats, resin with glass fibres (some centimetres long) in suspension used to be sprayed over the mould using equipment which had to be held by an operative. The workers’ respiratory system was protected using a local ventilation system and a mask.

In better-equipped yards special machines are used which cover the fibreglass sheets, previously spread by hand, with resin. The machines have hoods close to where the resin is emitted so that the emission of styrene (or other composite substance) is  restricted.

A preventitive system of this sort requires a hood of the correct size and shape for the operation involved. In the case of this machine the method in which the resin was spread was established and on the basis of this an efficient ventilation system was constructed.

In closed environments, including the sheds where the hull and wheelhouse are installed, ventilation plants guarantee the necessary change of air, limiting the accumulation of harmful substances in the environment.

One method for removing the risk of unacceptable toxins, such as carcinogens, is to substitute the substance with another which has the same functions.

The possibility, for example, of substituting polyester resin containing styrene with phenol resin has already been mentioned.

The choice of phenol resin carries other risks for the worker however, as some of these resins contain formaldehyde, which would be emitted as vapour and can damage the respiratory system.

There are however numerous phenol resins, so it is not difficult to choose one which does not present unacceptable risks to health.

For some years studies have been carried out to determine whether styrene is a carcinogen. If these studies have a positive outcome it is likely that the type of resin will be rapidly changed.

Trimming and cutting operations can be carried out under localised ventilation to limit the emission of dust and fibres.

Individual means of protection (IMP) may also be used in addition to the type of machinery described above. These include suitable clothing and footwear, gloves goggles, headwear, masks, earplugs and headphones.

The need to use particular IMPs such as masks, earplugs and headphones to protect the eardrums is evaluated by means of  monitoring carried out in the work environment.

The use of static absorbers of organic substances in the air is particularly useful to control the quality of air in the work environment.

Protection against injuries and fire must be in accordance with law and is not included in this study.