Alcohol production: the hidden costs

Every organisation is under pressure to save money, so the apparent initial cost savings of manufacturing 70% alcohol in-house are very attractive.

However, there are many hidden costs and significant risks associated with in-house alcohol production:

• Production efficiencies – the cost of downtime, dedicated staff, or staff taken away from their core activity to make alcohol

•Wastage and disposal costs of diluted alcohol and raw materials

• Validation and monitoring – this is time consuming and difficult (and may lead to audit failure if not done correctly)

• Health and safety risks of handling and storing bulk concentrate.

When 70% alcohol is made there are many steps to be undertaken and if correct procedures are not in place then errors or contamination could easily occur. This could be incorrect dilution or blending that makes the alcohol less effective as a disinfectant. Or it could be an error as basic as filtering sterile alcohol into a non-sterile bottle that will give a disinfectant that may be contaminated with bacterial spores. These spores could then be spread around the cleanroom.

To be most effective for disinfection IPA or denatured ethanol should normally be used at 70% concentration with water of suitable quality. For Grade A and B areas, this can be achieved by purchasing 95-99% alcohol and diluting it with Water for Injection (WFI). When calculating the cost per litre of the alcohol, most organisations take into account only the cost of the purchased alcohol. However, there are many, potentially hidden, costs to add.

Water for Injection can be expensive, so the cost of raw materials may be much higher than estimated. To obtain the correct dilution, a minimum quantity of 70% alcohol needs to be produced and this is often more than would be used in one disinfection session. So either there is a lot of wastage of alcohol and WFI, and the subsequent cost of waste disposal, or the 70% alcohol has to be stored longer, which requires validation and increases the risk of contamination from spores.

There is also the cost of storage space for the raw materials and empty bottles and the need for storage conditions to be carefully monitored. In some countries the volume of flammable liquids that can be stored is very small unless specific storage conditions are provided.

Staff costs

Either dedicated staff are employed to make the alcohol, or technicians need to be taken away from production to carry out this task. In some cases, production stops completely while technicians make the next batch of alcohol. Consideration needs to be given to the cost of staff time to assemble and prepare equipment; test to confirm correct dilution and blending; record data ;and ensure GMP compliance.

There is always a risk of incorrect dilution when alcohol and water are blended due to the immiscibility of the fluids. The top and bottom of every batch should be tested to ensure homogeneous mixing, otherwise bottles filled from the top of the container may contain 90% alcohol and bottles from the bottom 20% alcohol. This is even more crucial when the blending has been carried out manually.

GMP states that all disinfectants used in Grade A and B areas should be sterile prior to use. However, alcohol cannot be autoclaved due to its low flash point, so unless the alcohol can be sent out to an irradiation plant then the only other option to meet GMP requirements is to filter the alcohol into sterile bottles.

Validated process

Even if a company decides to sterilise only the bottles, GMP states that all sterilisation processes should be validated. Loading patterns need to be established and the validity of the process should be verified at regular intervals. Consideration should be given to the initial bioburden on the bottles and biological indicators (another cost) should be used as an additional monitoring device and records should be available for every batch.

Filtration is an important part of the process. There should not be a time delay between the product being filtered and sterilisation. Staff will need to: sterilise filters; integrity test them and record validation data. The integrity of a sterilised filter should be verified before use and confirmed immediately after use. The same filter cannot be used for more than one working day unless it has been validated.

Changing a filter every day to avoid validation costs caused one major UK pharmaceutical company to switch to sterile ready-to-use alcohol.

Overall, a validated sterilisation process is time-consuming and expensive, requiring not only storage and preparation areas, but also staff time to sterilise bottles, fill them and carry out validation of the sterilisation. Validation of sterility by QC will also be required.

GMP states that: “Disinfectants and detergents should be monitored for microbial contamination; dilutions should be kept in previously cleaned containers and should only be stored for defined periods unless sterilised.”

Unless sterile initially and protected from contamination during use, alcohol has a limited shelf life and much of the batch will therefore be wasted. When in use, the alcohol can become contaminated after only a few hours, unless the bottle incorporates a closed trigger spray system, so again there is significant wastage.

A UK manufacturing facility changed to a closed trigger spray system after their traditional spray bottles were found to contain fungal spores within 8 hours of opening in a Grade D environment.

When sterile alcohols are purchased from a reputable supplier, the sterility of the product is guaranteed, as each packaged bottle is gamma irradiated. Every step of the production process is validated and supported with technical information and batch certificates are supplied. The product has a two-year shelf life, enabling bulk purchase and minimising batch recording. The bottles are double bagged to enable easy transfer into the cleanroom.

70% IPA and denatured ethanol blended with either WFI or Deionised Water are available sterile and double-bagged in various formats especially for use in cleanrooms, with a hands-free dispenser option. There can be many benefits from purchasing sterile alcohol from a reputable supplier, not least of which is the minimised contamination risk. Other benefits include:

• No dilution errors

• No storage of opened bulk concentrate

• No cost for bulk containers

• No wastage of unused product due to long shelf life

• Simplified batch recording

• Minimised batch validation

• GMP compliance

• No re-sterilisation and validation costs

• No filtration costs, sterilisation of filters or replacement filters

• Supplied with full certification

• Saves production and QC staff time

• Minimises health and safety concerns, such as storing bulk containers of flammable liquid and injuries sustained from moving the heavy containers.

The decision between in-house production and buying in sterile alcohols should take into consideration more than just cost.