**4.3 Long term storage**

88 Current Frontiers in Cryobiology

and preparation for future fertility treatment. Usually several steps are required prior to initiation of semen storage. Most sperm banks only accept patients referred by their physician, however sometimes self referral is possible. Patients have to be screened by collection of blood, urine and semen samples to ensure that their samples will not contaminate others with infectious diseases when placed into storage. Consent for freezing and storage of semen has to be signed and witnessed. It is important that patients have a clear understanding of the process of banking and that they provide clear instructions on who is responsible for the disposition of the specimens in the event of their demise. Similarly, costs associated with banking and long term storage need to be clearly defined and assigned in case the patient becomes incapacitated. When samples are either used for procreation, transported to another facility, or storage is to be discontinued, the patient or designate must complete specific consent forms allowing the bank to comply with their wishes. In most countries it is assumed or stated by law that the semen belongs to the individual who produced the sample, and it is this individual who must sign all consents, unless the sample was designated for donation (e.g., in the case of anonymous sperm donation). If possible, multiple donations are usually recommended to ensure an adequate sperm reserve for future procreation, depending on the quality of the sample, individual

In most cases patients are able to produce an ejaculate by masturbation. Patients are given instructions to have minimum of 2 days and a maximum of 5 days of sexual abstinence, and to collect an entire ejaculate into a sterile specimen container. Condoms, creams or lubricants must not be used during collection as they can interfere with sperm motility and vitality due to the spermicidal properties of many products. Some patients would not be able to produce sample at the sperm bank by masturbation due to psychological, medical reasons or religious restrictions. In this case collection of samples by intercourse using a non-spermicidal condom, often referred to as a "semen collection device", is acceptable. Penile vibratory stimulation (PVS) can be helpful in spinal cord injury patients and those who are unable to produce semen by masturbation or intercourse (Brackett et al., 1998). However samples collected after PVS often exhibit relatively low motility (Hovav et al., 2002). PVS can help to produce a semen sample in most patients with spinal cord injuries

In some situations, collection of a retrograde sample is necessary. Retrograde ejaculation is a condition in which some or all of the sperm are not expelled through the urethra during ejaculation, but because of an incompetent bladder neck, the ejaculate refluxes back into the bladder. Reasons for this problem include organic conditions such as diabetes or multiple sclerosis, or pharmacological effects (eg. alpha adrenergic blocker use for hypertension). The general approach is to neutralize the urine pH and normalize the urine osmolarity by giving the patient sodium bicarbonate to alkalinize his urine. The urine sample is subsequently washed and used for insemination, in-vitro fertilization or cryopreservation. In patients with anejaculation, electro-ejaculation might be necessary to obtain semen, but this usually requires anaesthesia and has the associated risk of rectal injury. Additionally, samples produced by electro-ejaculation tend to be of relatively low quality (Denil et al., 1996).

circumstances and reason for sperm banking.

(Brackett et al., 1998).

**4.2 Methods of sperm collection and retrieval**

Proper long term storage is usually achieved by placing specimens in LN2 freezers, which have been safely used since the 1970s. Some automated systems are available and are capable of LN2 autofilling, supplied with alarms and data recordings for all activities and are designed to minimize the chances of loss or damage of samples. Despite automation, quality control procedures must be implemented by sperm banks to ensure proper monitoring and safety of samples and staff. The LN2 itself can be a source of microbial contamination so every available practical step has to be considered to reduce the risk of transmission (Fountain et al., 1997). In general cross-contamination of frozen samples by pathogens are extremely rare, and have not been reported in the setting of sperm banks. It is, however, theoretically possible, as often patients are not fully screened prior to freezing, as in cases of autologous sample cryopreservation or due to time constraints for oncology banking (Clarke, 1999). "Quarantine'" tanks are often used to separate samples with pending, unclear laboratory results or unscreened patients. However, contamination is still possible, as released samples that are moved to long term storage could have acquired pathogenic contamination from one of other "pending" samples in the quarantine tank. When samples are cryopreserved for patients with known infections such as HIV or hepatitis B and C carriers, separate tanks for each type of infection are required (Tomlinson & Sakkas, 2000). Cross-contamination can also be avoided by storage of samples in nitrogen vapour. However, in contrast to liquid nitrogen, there are some concerns that vapour has poor heat transfer rates, lower thermal capacity, and significant temperature fluctuation may exist within the vapour(Tomlinson & Saakas, 2000; Wood, 1999). Some older types of vapour storage systems could only guarantee the maintenance of temperature around - 100°C and were not acceptable for long term sperm storage. Storage temperatures have to be maintained below -135°C to ensure a glass-like condition of frozen water and for secure long

Cryopreservation of Human Spermatozoa

by Vitrification *vs.* Slow Freezing: Canadian Experience 91

sperm cryopreservation have created opportunities for many families to achieve pregnancies through therapeutic donor insemination or IVF with donor sperm. Pregnancy rates are estimated to be around 10-12% per unstimulated cycle and can be achieved when at least 5 × 106 progressively motile spermatozoa inseminated into the lower cervical canal on 2–3 occasions during the ovulatory phase of menstrual cycle (Scott et al., 1990). At present, some 30,000 births per year worldwide are attributable to frozen donor sperm inseminations (Mortimer, 2004). While this seems like a large number, it may fall in the future, as the recruitment of sperm donors is increasingly difficult due to complicated and

The screening process for donor sperm is quite rigorous and includes obtaining a complete medical and sexual history, physical examination, psychological assessment and laboratory work-up on blood, urine and semen specimens to screen for pathogens including Hepatitis B, C, Human Immunodeficiency Virus (HIV 1&2), Human T-cell Lymphotrophic Virus (HTLV 1&2), Treponema pallidum (Syphilis), Cytomegalovirus, Chlamydia trachomatis and Neisseria gonorrhoea. Sperm banks perform genetic screening for heritable diseases based on the ethnic background of sperm donors (eg. Cystic Fibrosis for Caucasians). Donors must be retested after the required quarantine interval, and specimens may be released only if the results of repeat testing are negative. Specimens can only be used after they have been quarantined for a minimum of 180 days to avoid the risk of HIV transmission. Donor eligibility restrictions apply to employees of sperm banks, poor donors' health or quality of the semen and in some countries by sexual orientation of the donor, as gay or bisexual men are considered at higher risk for HIV and prohibited from being sperm donors in some countries (including Canada and USA). Many countries have age restrictions for sperm donation. The minimum age is usually 18 and the maximum 40 years of age (Health Canada

Semen donors can be classified into two specific groups, anonymous and non-anonymous (known). Currently, with the establishment of many commercial sperm banks and the ability to safely transport samples even between continents, anonymous sperm donation is the method of choice for most recipients. The anonymity of the donor is maintained through the process. This is an important issue to both the recipient and the donor (Ernst et al., 2007). For fully anonymous sperm donation, the recipients would not be known to the donor and the donor offspring would have no future contact with the donor. The sperm donor gives up all legal rights over the biological children conceived from his samples donated to sperm bank. Anonymous donation allows parents, if they wish, to conceal the issue of infertility, or the fact of non-genetic parenting from the offspring. The motivation to hide this information most commonly is driven by pressure from other family members; fear of being rejected by the child or to protect children from the complicated psychosocial matters related to sperm donation. In many Western countries disclosure is encouraged by many counsellors, and if open disclosure is chosen by the parents, it is usually advised to disclose the method of conception to their children at an early age. Non-disclosure by parents of the biological origin of their children is viewed by some as misleading the child and could potentially affect trust between parents and their children, if their origin eventually becomes known to the child (Patrizio et al., 2001). However, it is ultimately the decision of the parents to

strict regulatory procedures, as well as lack of interest from potential donors.

2000, American Society for Reproductive Medicine (ASRM), 2004)

**5.2 Anonymous donors**

disclose or not as in adoption cases.

term storage of semen samples (Clarke, 1999). Newer types of high efficiency LN2 vapour freezers and others that have a LN2 "jacket"' provide working environments of below - 160°C and are more suitable for sperm banks.


**1. Introduction**

Generally, corrosion is regarded as the loss of a metal by the influence of corrosive agents [1]. However, in a broad sense, corrosion is the devastative consequence of chemical reaction between a metal or metal alloy and its environment [2]. General corrosion or uniform corrosion is the most prevalent form of corrosion that takes place on an entirely exposed metal surface *via* the electrochemical reactions in atmospheric or aqueous media and continues uniformly to cause the greatest destruction of that metal [3]. Even though only metals come to mind when describing corrosion, non-metallic materials, such as plastics, concrete, ceramics, rubber, etc. are prone to corrosion as well when exposed to different corrosive environments [4].

The difference in the potential energies of the corroding metal and the corrosion product is the fundamental force that drives the corrosion reaction. A certain amount of energy is required to be provided to naturally occurring minerals and ores to extract metals from them. Therefore, it is natural that these metals tend to revert back to their original state from which they were obtained when they are exposed to their environments. It is noteworthy that each metal is different in terms of the amount of energy required and stored in it or that is released during its corrosion. The greater the amount of energy needed during metal extraction, the more thermodynamically unstable is the metal and the shorter is its temporary existence in metallic form. Hence, corrosion has also been defined as the reverse of extractive metallurgy [1, 5].The electrochemical dissolution of a metal is the most important mechanism involved in its corrosion and makes the basis of all uniform and localized corrosion types. However, there are some corrosion types, such as oxidation, fretting corrosion, molten salt corrosion, etc. that can be described without reference to electrochemistry [1]. The mechanism of corrosion attack in an atmospheric environment and in an aqueous environment will be always governed by some

aspect of electrochemistry. Electrons will be flowing from certain areas of a metal surface to other areas through an electrolyte that is capable of conducting ions. This stems from the incredible tendency of metals to react electrochemically with water, oxygen, and other substances in the aqueous environment. In an electrochemical corrosion process, the anode is that area of the metal surface that is corroding due to the loss of electrons while the cathode is the area that consumes the electrons generated by the corrosion reaction [6].

Almost all of us are familiar with corrosion happening to metal structures, boats, steel pilings, household utensils, etc. Unfortunately, many of us are not aware of corrosion that is deteriorating the properties of underground water, oil, and gas pipelines crisscrossing our land or water pipes in the home where corrosion occurs mostly from the inside. Successful enterprises put in considerable efforts in controlling corrosion at the design stage and in the operational phase to avoid major corrosion failures, such as unscheduled shutdowns, fatalities, personal injuries, and environmental contamination in a modern business environment. However, even the best design is unable to foresee all conditions that can allow corrosion intruding into the life of a system [5]. Steel reinforced bar (rebar) can corrode in concrete without being noticed at all and can cause damage to buildings, bridges, parking structures, the collapse of electrical towers, failure of a section of highway, etc., resulting in a huge amount of repairing cost and threatening public safety [7]. This is why regular maintenance of the metallic components that are susceptible to corrosion is of paramount importance.

### **2. Impact of corrosion**

Even though the main reasons for considering corrosion are economic and ecological, losses due to corrosion or costs of corrosion can be actually divided into three main categories as shown in **Figure 1** [8].

#### **2.1 Material and energy**

The impact of corrosion on the equipment and its surrounding deserves a huge attention when it comes to designing an industry. Corrosion is considered to be one of the most challenging issues for most of the industrialized countries. Corrosion of tanks, piping, metal components of machines, bridges, ships, etc. can incur a massive material and economic losses upon a nation. Additionally, the safety of operating equipment, such as boilers, pressure vessels, metallic containers for toxic chemicals, bridges, turbine blades and rotors, automotive steering mechanisms, and airplane components can be threatened by corrosion failure [8]. Furthermore, the

**79**

costs can be assessed.

*Green Corrosion Inhibitors*

**2.2 Economic**

*DOI: http://dx.doi.org/10.5772/intechopen.81376*

by the world is used to replace rusted steel [10].

well as those related to users (indirect) [5, 12].

devastative impact of corrosion goes beyond the metals and extends to energy, water, and the manufacturing phase of the metal frames [9]. It has been reported that one ton of steel turns into rust every 90 seconds, and, on the contrary, the energy needed to manufacture one ton of steel is approximately equal to the energy an average family consumes over 3 months. Approximately 50% of every ton of steel produced

Economic losses are classified into two types: (i) direct losses and (ii) indirect losses. Replacing the corroded structures and machinery of their components, for instance, mufflers, condenser tubes, pipelines, metal roofing, including necessary labor, repainting structures to prevent rusting, maintenance cost of cathodic protection system for underground pipelines, replacement cost of millions of domestic hot-water tanks and automobile mufflers, extra cost of using corrosion-resistant metals and alloys, galvanizing or nickel plating of steel, addition of corrosion inhibitors to water, and dehumidifying cost of the metal equipment storage rooms contribute to the direct losses. While it is quite difficult to assess the indirect losses, they have still been reported to add several billion dollars to the direct losses. Indirect losses include sudden shutdown of plants, loss of water, gas, or oil through a corroded pipeline, loss of efficiency in the energy conversion systems imposed by corrosion processes, contamination of water and food products in metal piping and containers, and overdesign requiring equipment to be designed many times heavier than normal operating pressure or applied stress to extend their lifetime [8]. Uhlig made the first ever systematic study on the cost of corrosion in 1949 [11]. Uhlig's report estimated the annual cost of corrosion in the United States to be US\$ 5.5 billion or 2.1% of the 1949 gross national product (GNP). This study measured the total costs by summing the costs related to anti-corrosion materials and corrosioninduced maintenance and replacement handled by owners and operators (direct) as

Corrosion cost studies using different methods, such as Uhlig method invented by Uhlig in 1949 [11], Hoar method invented by Hoar in 1971 [13], and economic input/output model devised by National Bureau of Standards (NBS) collaborating with Battelle Memorial Institute in 1978 [14] have been undertaken by several major economies, including Australia, China, Finland, Germany, India, Japan, Kuwait, the United Kingdom, and the United States [15]. A common observation of these studies was that the costs of corrosion ranged from approximately 1–5% of the GNP of each nation. The variation in the corrosion cost with respect to GNP was ascribed to the methodology used by each study and the specifics of each country [12].

A study done by National Association of Corrosion Engineers (NACE) as part of its International Measures of Prevention, Application, and Economics of Corrosion Technologies Study (IMPACT) revealed that the global cost of corrosion in 2013 was estimated to be US\$ 2.5 trillion which was equivalent to 3.4% of the global GDP in that year [15]. This study utilized the World Bank economic sector and GDP data to relate the cost of corrosion studies to a global cost of corrosion. In order to address the economic sectors across the world, the global economy was divided into economic regions with similar economies (according to World Bank). These were: United States, European Region, India, Arab World (defined by the World Bank), Russia, China, Japan, Four Asian Tigers plus Macau, and Rest of the World. However, the costs estimated typically do not include environmental consequences or individual safety. It is noteworthy that receiving additional funds for corrosion studies, or updated information on these studies, more detailed and accurate global

**Figure 1.** *Breakdown of corrosion costs.*

#### *Green Corrosion Inhibitors DOI: http://dx.doi.org/10.5772/intechopen.81376*

devastative impact of corrosion goes beyond the metals and extends to energy, water, and the manufacturing phase of the metal frames [9]. It has been reported that one ton of steel turns into rust every 90 seconds, and, on the contrary, the energy needed to manufacture one ton of steel is approximately equal to the energy an average family consumes over 3 months. Approximately 50% of every ton of steel produced by the world is used to replace rusted steel [10].