Introduction

The 20th Century has brought with it tremendous gains in science and technology as well as gains in the quality of human life and longevity. However, these gains have been accompanied by certain hazards, many associated with the 1 00,000 chemicals which are now commonly in use. Reproductive hazards are one such hazard which has accompanied the "chemical revolution".

Substances which can cause mutations, birth defects, abortions, and infertility or sterility are called reproductive toxins. Lead, certain polynuclear aromatic hydrocarbons, cadmium, ethylene oxide and ethylene glycol are examples of reproductive toxins. Sexually transmitted diseases can also affect fertility and offspring so that even reproduction itself can be a reproductive hazard.

For many years the control of exposure to hazardous chemicals in the workplace was limited to substances which affected the workers themselves, but today we are concerned with controlling exposures to chemicals which can affect future generations. According to a recent article in the journal of the American Industrial Hygiene Association, "disorders of reproduction, infertility, spontaneous abortion, teratogenesis" are among the top 1 0 work related diseases and injuries in the United States.

An awareness of the reproductive hazards of chemicals dates back to Roman times when lead used in pottery contributed to the incidence of stillbirths. More recently, regulations and guidelines for identifying reproductive hazards, as well as corporate policies and laws for controlling workplace exposures have been established as a result of the tragedy of thalidomide babies during the 1960s. Babies with short, 'fin-like" arms and legs were born to pregnant women who were prescribed thalidomide for nausea.

Different Types of Reproductive Hazards

Today lead is known to be an abortifacient (something which causes an artificial abortion) and can produce teratospermias (abnormal sperm). In the late 1970s a widely used soil fumigant (DBCP - dibromochloropropane) was found to cause sterility in male factory workers who produced ft. Furthermore, ft was found that farm workers who applied DBCP had significantly reduced sperm counts. Low sperm counts, abnormal sperm, and infertility have been associated with work places such as battery plants, lead mines, and industries using large amounts of organic solvents such as toluene, benzene, and xylene.

Mutagens are agents which can cause mutations and do so by affecting the germ lines (egg and sperm); this means that exposure to either parent can affect the offspring. This type of agent causes damage before conception and can result in infertility, unsuccessful fertilization or implantation or fetal abnormality. An example of a mutagen is a chemical called 2-acetylaminofluorine.

Teratogens are agents which usually require maternal exposure after conception and which can cause damage to the developing fetus resulting in death or abnormality. Fetal alcohol syndrome (FAS) where the offspring can be mildly or severely deformed or developmentally retarded, is caused by high maternal consumption of alcohol during pregnancy. Some suggest that the male semen can contain substances absorbed from his body which become absorbed by the vaginal mucosa and subsequently have a teratogenic affect on the developing fetus. It has been suggested that this might also be the case with FAS. Teratogens should be particularly avoided during the first trimester of pregnancy when the developing fetus is at greatest risk from this type of agent.

Possible Exposure Routes of Reproductive Toxins

Carbon disulphide, various pesticides and rodenticides, 2-acetylaminofluorine (2-AAF), some amides, benzene, toluene and xylene are among the types of compounds which can act as reproductive toxins and which may be found at restricted locations on campus.

The workplace is not the only place where exposure to mutagens and teratogens can take place. Cigarette smoke, carbon monoxide (also contained in cigarette smoke), alcohol, and even vitamin A have been implicated as teratogenic agents.

Some guidelines to follows are:

1. Avoid direct or second-hand smoke, alcohol and other recreational drugs and consult a physician before taking any medicines.

2. Female laboratory workers are advised to inform HSEO as soon as a pregnancy is known so that a workplace evaluation can be performed to ensure no exposure to teratogens.

3. Anything that might be hazardous to an adult will be even more hazardous to the developing fetus.

HSEO has implemented ongoing exposure assessment and medical surveillance programs to evaluate exposures of HKUST students and employees to a variety of hazardous chemicals. HSEO adheres to the As Low As Reasonably Achievable (ALARA) principle in addressing occupational exposure to hazardous chemicals, including reproductive toxins. We make every effort to ensure that there will not be exposures in excess of local or internationally accepted limits.

HSEO is committed to assisting you in ensuring a safe workplace. If you are working with substances which have reproductive effects, please contact us so that we can evaluate your exposure and recommend intervention strategies to control exposures.

Chemicals play an important role in many workplace applications. The inherent hazards of chemicals can be reduced by minimizing the quantity of chemicals on hand. However, when chemicals must be in-house, proper storage and handling can reduce or eliminate associated risks.

Proper storage information can usually be obtained from the Safety Data Sheet (SDS), label or other chemical reference material. An SDS must be on hand for every chemical in your workplace. The SDS and chemical label can be consulted for information on special storage requirements. The SDS can also answer questions such as:

• Is the chemical a flammable or combustible?

• Is the chemical a corrosive?

• Does the chemical need to be stored at other than ambient temperature?

• Is the chemical an oxidizer or reducer?

• Is the chemical light-sensitive?

• Does the chemical require any special handling procedures?

Typical storage considerations may include temperature, ignition control, ventilation, segregation and identification. Proper segregation is necessary to prevent incompatible materials from inadvertently coming into contact. If incompatible materials were to come into contact, fire, explosion, violent reactions or toxic gases could result. When segregating chemicals, acids should not be stored with bases, and oxidizers should not be stored with organic materials or reducing agents. A physical barrier and/or distance is effective for proper segregation.

If cabinets are used to segregate chemicals, consider the compatibility of the chemicals with the cabinet. For example, corrosives like strong acids and caustics will corrode most metal cabinets. Non-metallic or epoxy painted cabinets are available and will provide a better service life with these types of chemicals. However, it is recommended that hydrochloric acid not be stored in any metal cabinet. Some other acids and bases may damage the painted surfaces of a cabinet if a spill occurs. Also, perchloric acid should not be stored in a wooden cabinet.

There are cabinets available specifically for flammable and combustible materials. It is important to be aware of maximum allowable container size and maximum quantities for storage in cabinets based on the class of the flammable. The class of a flammable or combustible is determined by its flash point and boiling point.

For ease of locating chemicals, many storerooms organize chemicals alphabetically. However, chemical storage based upon an alphabetical arrangement of chemicals may inadvertently locate incompatible materials in close proximity. A few examples of this potentially dangerous storage method are demonstrated by the following pairs of incompatible materials:

Examples of incompatible materials are listed below. The material on the left should be stored and handled so that it does not contact the incompatible chemical(s) on the right which would result in a potential violent reaction or toxic reaction products.