This is a reasonable thing to ask and you should ask it of any company you hire. Below is what we do, what we would want to know if it were our home, and the questions that separate a careful contractor from a careless one.
Note. This page is general guidance about treatment practice. It is not medical advice. If someone in the household is pregnant, has asthma or a respiratory condition, or is immunocompromised, ask your doctor as well as us, and tell us the answer.
Ask these four questions before you book anyone
- "Which product will you use, and can I see the registration and the safety data sheet?" Products used for household and public health pest control in Vietnam must hold a circulation registration number issued by the Ministry of Health. A company that cannot show you the registration and the safety data sheet for the specific product it is about to use in your home is not one to hire.
- "How long do we need to stay out, and what is that based on?" A real answer is specific to the product and the method. "A couple of hours, should be fine" is not an answer.
- "Can this be done with gel and bait instead of spraying?" For cockroaches and ants the answer is very often yes — see below.
- "What do I do about the fish tank?" If the answer is vague, stop. This is the question that catches out careless operators.
The method matters more than the product
The safest treatment is usually the one that puts the least material into the air you breathe.
- Gel bait and bait stations — for cockroaches and ants. Placed in cracks, hinges and the backs of cabinets, out of reach. Nothing is aerosolised, so there is no re-entry wait at all in most cases. Often more effective than spraying, because the insects carry it back to the nest. If you have a small child or you are pregnant, ask for this first.
- Residual application to surfaces — applied along skirting boards, behind and under furniture, at door frames. Targeted, low volume, dry within a couple of hours. This is the normal backbone of an apartment treatment.
- Space spraying, fogging and ULV — fills the air of a room. Effective against flying insects, and the method with the longest re-entry wait. We use it where it is genuinely needed, not as a default.
- Physical measures — screens, traps, sealing gaps, removing standing water. Zero chemical, and it is what makes everything else last.
Re-entry times
The waiting period depends on the product and method, and we give you the specific figure in writing on the day rather than a generic one. As a rough guide: a targeted gel or bait placement usually needs no wait; a residual surface application typically needs the treated surfaces to dry and the room ventilated; a space spray or fog needs the longest wait and thorough airing afterwards. For a household with an infant or a pregnant resident we would normally recommend staying out longer than the minimum and ventilating well before returning.
Specific precautions
Babies and young children
- Remove or cover the cot, mattress, changing mat and soft toys before treatment.
- Bottles, dummies, bibs and feeding equipment go in a closed cupboard.
- Wash floors in the crawling area after the re-entry period has passed — not before, or you remove the treatment.
- Ask for bait rather than spray wherever the pest allows it.
Cats and dogs
- Out of the property for the treatment and the full re-entry period.
- Food and water bowls, bedding and litter trays removed or sealed.
- Cats groom constantly, so they pick up anything on floors and low surfaces. Tell us you have a cat — it changes both product choice and placement.
- Bait stations for rodents must be tamper-resistant and placed where a dog cannot reach them. Say if you have a dog that opens things.
Fish and aquariums
The single most important item on this page. Many insecticides are highly toxic to fish and to invertebrates, and an aquarium air pump will actively draw airborne material into the water. Tell us before the visit. The tank must be covered and sealed, and the pump switched off for the treatment period. If the tank is large or the treatment is a space spray, we will discuss whether to treat that room at all.
Birds and reptiles
Birds are more sensitive to airborne substances than mammals are. Cages should be moved out of the property entirely, not to another room. The same applies to reptile enclosures with their own ventilation.
Pregnancy
We are not doctors and will not pretend otherwise. What we do: use bait and targeted placement instead of space spraying wherever the pest allows it, recommend a longer absence than the minimum, ventilate thoroughly before you return, and give you the product name and registration in advance so you can show it to your doctor. If your doctor advises against any treatment during a particular stage, we can do the physical work — screening, sealing, removing breeding water, trapping — and postpone the rest.
What we will refuse to do
We will not treat a room with an uncovered aquarium, will not space-spray a bedroom with an infant sleeping elsewhere in a small apartment without discussing it first, and will not tell you a treatment is "completely harmless". Everything effective enough to kill an insect deserves to be handled with care, and a company that tells you otherwise is telling you what you want to hear.
Reading in Vietnamese?
Global Pest Control is the English-language site of Khử Trùng Toàn Cầu. These pages cover the same work for Vietnamese-speaking customers, and carry the full price tables.